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Most hormone dependent cancers become resistant to treatment after one to three years and resume growth despite hormone therapy. Previously considered "hormone-refractory prostate cancer" or "androgen-independent prostate cancer", the term castration-resistant has replaced "hormone refractory" because while they are no longer responsive to castration treatment (reduction of available androgen/testosterone/DHT by chemical or surgical means), these cancers still show reliance upon hormones for androgen receptor activation.
The cancer chemotherapic docetaxel has been used as treatment for CRPC with a median survival benefit of 2 to 3 months. A second-line chemotherapy treatment is cabazitaxel. A combination of bevacizumab, docetaxel, thalidomide and prednisone appears effective in the treatment of CRPC.
The immunotherapy treatment with sipuleucel-T in CRPC increases survival by 4 months. The second line hormonal therapy abiraterone increases survival by 4.6 months when compared to placebo. Enzalutamide is another second line hormonal agent with a 5-month survival advantage over placebo. Both abiraterone and enzalutamide are currently being tested in clinical trials in those with CRPC who have not previously received chemotherapy.
Only a subset of people respond to androgen signaling blocking drugs and certain cells with characteristics resembling stem cells remain unaffected. Therefore, the desire to improve outcome of people with CRPC has resulted in the claims of increasing doses further or combination therapy with synergistic androgen signaling blocking agents. But even these combination will not affect stem-like cells that do not exhibit androgen signaling. It is possible that for further advances, a combination of androgen signaling blocking agent with stem-like cell directed differentiation therapy drug would prove ideal.
Palliative care is medical care which focuses on treatment of symptoms of serious illness, like cancer, and improving quality of life. One of the goals of treatment in palliative care is symptom control rather than a cure of the underlying cancer. Pain is common in metastatic prostate cancer, and cancer pain related to bone metastases can be treated with bisphosphonates, medications such as opioids, and palliative radiation therapy to known metastases. Spinal cord compression can occur with metastases to the spine and can be treated with steroids, surgery, or radiation therapy. Other symptoms that can be addressed through palliative care include fatigue, delirium, lymphedema in the scrotum or penis, nausea, vomiting, and weight loss.
Many treatment options for cancer exist. The primary ones include surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy and palliative care. Which treatments are used depends on the type, location and grade of the cancer as well as the patient's health and preferences. The treatment intent may or may not be curative.
Chemotherapy is the treatment of cancer with one or more cytotoxic anti-neoplastic drugs (chemotherapeutic agents) as part of a standardized regimen. The term encompasses a variety of drugs, which are divided into broad categories such as alkylating agents and antimetabolites. Traditional chemotherapeutic agents act by killing cells that divide rapidly, a critical property of most cancer cells.
Targeted therapy is a form of chemotherapy that targets specific molecular differences between cancer and normal cells. The first targeted therapies blocked the estrogen receptor molecule, inhibiting the growth of breast cancer. Another common example is the class of Bcr-Abl inhibitors, which are used to treat chronic myelogenous leukemia (CML). Currently, targeted therapies exist for breast cancer, multiple myeloma, lymphoma, prostate cancer, melanoma and other cancers.
The efficacy of chemotherapy depends on the type of cancer and the stage. In combination with surgery, chemotherapy has proven useful in cancer types including breast cancer, colorectal cancer, pancreatic cancer, osteogenic sarcoma, testicular cancer, ovarian cancer and certain lung cancers. Chemotherapy is curative for some cancers, such as some leukemias, ineffective in some brain tumors, and needless in others, such as most non-melanoma skin cancers. The effectiveness of chemotherapy is often limited by its toxicity to other tissues in the body. Even when chemotherapy does not provide a permanent cure, it may be useful to reduce symptoms such as pain or to reduce the size of an inoperable tumor in the hope that surgery will become possible in the future.
Superficial tumors (those not entering the muscle layer) can be "shaved off" using an electrocautery device attached to a cystoscope, which in that case is called a resectoscope. The procedure is called transurethral resection of bladder tumor—TURBT—and serves primarily for pathological staging. In case of non-muscle invasive bladder cancer the TURBT is in itself the treatment, but in case of muscle invasive cancer, the procedure is insufficient for final treatment.
Immunotherapy by intravesicular delivery of Bacillus Calmette–Guérin (BCG) is also used to treat and prevent the recurrence of superficial tumors. BCG is a vaccine against tuberculosis that is prepared from attenuated (weakened) live bovine tuberculosis bacillus, Mycobacterium bovis, that has lost its virulence in humans. BCG immunotherapy is effective in up to 2/3 of the cases at this stage, and in randomized trials has been shown to be superior to standard chemotherapy. The mechanism by which BCG prevents recurrence is unknown, but the presence of bacteria in the bladder may trigger a localized immune reaction which clears residual cancer cells.
Patients whose tumors recurred after treatment with BCG are more difficult to treat. Many physicians recommend cystectomy for these patients. This recommendation is in accordance with the official guidelines of the European Association of Urologists (EAU) and the American Urological Association (AUA) However, many patients refuse to undergo this life changing operation, and prefer to try novel conservative treatment options before opting to this last radical resort. Device assisted chemotherapy is one such group of novel technologies used to treat superficial bladder cancer. These technologies use different mechanisms to facilitate the absorption and action of a chemotherapy drug instilled directly into the bladder. Another technology - electromotive drug administration (EMDA) – uses an electric current to enhance drug absorption after surgical removal of the tumor. Another technology, thermotherapy, uses radio-frequency energy to directly heat the bladder wall, which together with chemotherapy shows a synergistic effect, enhancing each other's capacity to kill tumor cells. This technology was studied by different investigators.
In order to address the problem of micrometastatic disease which in itself has implications on longtime survival, new treatment options are dearly needed. Micrometastatic dissemination is often not treatable with only major surgery and the concept of neoadjuvant chemotherapy has evolved. In this patients first receive chemotherapy in 3 or 4 cycles, and after that proceed to major surgery. In a number of meta-analyses of randomised prospective trials worldwide, the results have shown survival benefits between 5–8% with this therapy, in a follow up time of 5 years.
The goals of the treatment for bone metastases include pain control, prevention and treatment of fractures, maintenance of patient function, and local tumor control. Treatment options are determined by multiple factors, including performance status, life expectancy, impact on quality of life, and overall status of clinical disease.
Pain management
The World Health Organization's pain ladder was designed for the management of cancer-associated pain, and mainly involves various strength of opioids. Mild pain or breakthrough pain may be treated with nonsteroidal anti-inflammatory drugs.
Other treatments include bisphosphonates, corticosteroids, radiotherapy, and radionucleotides.
Percutaneous osteoplasty involves the use of bone cement to reduce pain and improve mobility. In palliative therapy, the main options are external radiation and radiopharmaceuticals. High-intensity focused ultrasound (HIFU) has CE approval for palliative care for bone metastasis, though treatments are still in investigatory phases as more information is needed to study effectiveness in order to obtain full approval in countries such as the USA.
Thermal ablation techniques are increasingly being used in the palliative treatment of painful metastatic bone disease. Although the majority of patients experience complete or partial relief of pain following external radiation therapy, the effect is not immediate and has been shown in some studies to be transient in more than half of patients. For patients who are not eligible or do not respond to traditional therapies ( i.e. radiation therapy, chemotherapy, palliative surgery, bisphosphonates or analgesic medications), thermal ablation techniques have been explored as alternatives for pain reduction. Several multi-center clinical trials studying the efficacy of radiofrequency ablation in the treatment of moderate to severe pain in patients with metastatic bone disease have shown significant decreases in patient reported pain after treatment. These studies are limited, however, to patients with one or two metastatic sites; pain from multiple tumors can be difficult to localize for directed therapy. More recently, cryoablation has also been explored as a potentially effective alternative as the area of destruction created by this technique can be monitored more effectively by CT than radiofrequency ablation, a potential advantage when treating tumors adjacent to critical structures.
Monthly injections of radium-223 chloride (as Xofigo, formerly called Alpharadin) have
been approved by the FDA in May 2013 for castration-resistant prostate cancer (CRPC) with bone metastases.
A Cochrane review of calcitonin for the treatment of metastatic bone pain indicated no benefit in reduction of bone pain, complications, or quality of life.
Therapy is based on staging and patient condition and utilizes one or more of the following approaches.
Surgery is the mainstay of therapy if feasible involving total abdominal hysterectomy with bilateral salpingo-oophorectomy. Other approaches include radiation therapy, chemotherapy, and hormonal therapy.
Prognosis is relatively poor.
In general, treatment for soft-tissue sarcomas depends on the stage of the cancer. The stage of the sarcoma is based on the size and grade of the tumor, and whether the cancer has spread to the lymph nodes or other parts of the body (metastasized). Treatment options for soft-tissue sarcomas include surgery, radiation therapy, and chemotherapy.
- Surgery is the most common treatment for soft-tissue sarcomas. If possible, the doctor will remove the cancer and a safe margin of the healthy tissue around it. It is important to obtain a margin free of tumor to decrease the likelihood of local recurrence and give the best chance for eradication of the tumor. Depending on the size and location of the sarcoma, it may, rarely, be necessary to remove all or part of an arm or leg.
- Radiation therapy may be used either before surgery to shrink tumors or after surgery to kill any cancer cells that may have been left behind. In some cases, it can be used to treat tumours that cannot be surgically removed. In multiple studies, radiation therapy has been found to improve the rate of local control, but has not had any influence on overall survival.
- Chemotherapy may be used with radiation therapy either before or after surgery to try to shrink the tumor or kill any remaining cancer cells. The use of chemotherapy to prevent the spread of soft-tissue sarcomas has not been proven to be effective. If the cancer has spread to other areas of the body, chemotherapy may be used to shrink tumors and reduce the pain and discomfort they cause, but is unlikely to eradicate the disease.
Treatment is usually multimodal, involving surgery, chemotherapy and radiotherapy:
- Surgery, to remove the tumor and a safety margin of healthy tissue. This is the mainstay of synovial sarcoma treatment and is curative in approximately 20–70% of patients, depending on the particular study being quoted.
- Conventional chemotherapy, (for example, doxorubicin hydrochloride and ifosfamide), to reduce the number of remaining microscopic metastases. The benefit of chemotherapy in synovial sarcoma to overall survival remains unclear, although a recent study has shown that survival of patients with advanced, poorly differentiated disease marginally improves with doxorubicin/ifosfamide treatment.
- Radiotherapy to reduce the chance of local recurrence. The benefit of radiotherapy in this disease is less clear than for chemotherapy.
Treatment consists of surgical excision (the extent of which ranges from tumor excision to limb amputation, depending on the tumor) and in almost all cases radiation. Radiation eliminates the need for limb amputation and there is level I evidence to show that it leads to equivalent rates of survival (Rosenberg et al. NCI Canada). Radiation may be delivered either pre-op or post-op depending on surgeon and multidisciplinary tumor board's recommendations. Radiation can be omitted for low grade, Stage I excised tumors with >1 cm margin (NCCN). Chemotherapy remains controversial in MFH.
The usual site of metastatic disease is the lungs, and metastases should be resected if possible. Unresectable or inoperable lung metastasis may be treated with stereotactic body radiation therapy (SBRT) with excellent local control. However, neither surgery nor SBRT will prevent emergence of additional metastasis elsewhere in the lung. Therefore, role of chemotherapy needs to be further explored to address systemic metastasis.
Selective α-blockers are the most common choice for initial therapy. They include alfuzosin, doxazosin, silodosin, tamsulosin, and terazosin. They have a small to moderate benefit. All five are equally effective but have slightly different side effect profiles. Alpha blockers relax smooth muscle in the prostate and the bladder neck, thus decreasing the blockage of urine flow. Common side effects of alpha blockers include orthostatic hypotension (a head rush or dizzy spell when standing up or stretching), ejaculation changes, erectile dysfunction, headaches, nasal congestion, and weakness.
Tamsulosin and silodosin are selective α1 receptor blockers that preferentially bind to the α1A receptor in the prostate instead of the α1B receptor in the blood vessels. Less-selective α1 receptor blockers such as terazosin and doxazosin may lower blood pressure. The older, less selective α1-adrenergic blocker prazosin is not a first line choice for either high blood pressure or prostatic hyperplasia; it is a choice for patients who present with both problems at the same time. The older, broadly non-selective alpha blocker medications such as phenoxybenzamine are not recommended for control of BPH. Non-selective alpha blockers such as terazosin and doxazosin may also require slow dose adjustments as they can lower blood pressure and cause syncope (fainting) if the response to the medication is too strong.
The 5α-reductase inhibitors finasteride and dutasteride may also be used in men with BPH. These medications inhibit the 5α-reductase enzyme, which, in turn, inhibits production of DHT, a hormone responsible for enlarging the prostate. Effects may take longer to appear than alpha blockers, but they persist for many years. When used together with alpha blockers, no benefit was reported in short-term trials, but in a longer term study (3–4 years) there was a greater reduction in BPH progression to acute urinary retention and surgery than with either agent alone, especially in patients were more severe symptoms and larger prostates. Other trials have confirmed reductions in symptoms, within 6 months in one trial, an effect that was maintained after withdrawal of the alpha blocker. Side effects include decreased libido and ejaculatory or erectile dysfunction. The 5α-reductase inhibitors are contraindicated in pregnant women because of their teratogenicity due to interference with fetal testosterone metabolism, and as a precaution, pregnant women should not handle crushed or broken tablets.
Kaposi sarcoma is not curable, but it can often be treatable for many years. In KS associated with immunodeficiency or immunosuppression, treating the cause of the immune system dysfunction can slow or stop the progression of KS. In 40% or more of peoples with AIDS-associated Kaposi sarcoma, the Kaposi lesions will shrink upon first starting highly active antiretroviral therapy (HAART). However, in a certain percentage of such people, Kaposi sarcoma may again grow after a number of years on HAART, especially if HIV is not completely suppressed.
People with a few local lesions can often be treated with local measures such as radiation therapy or cryosurgery. Weak evidence suggests that antiretroviral therapy in combination with chemotherapy is more effective than either of those two therapies individually. Limited basic and clinical evidence suggest that topical beta-blockers, such as timolol, may induce regression of localized lesions in classic as well as HIV-associated Kaposi sarcoma. In general, surgery is not recommended, as Kaposi sarcoma can appear in wound edges. In general, more widespread disease, or disease affecting internal organs, is treated with systemic therapy with interferon alpha, liposomal anthracyclines (such as Doxil) or paclitaxel.
Treatment depends upon the site and the extent of the disease. Clear cell sarcoma is usually treated with surgery in the first place in order to remove the tumor. The surgical procedure is then followed by radiation and sometimes chemotherapy. Few cases of clear cell sarcoma respond to chemotherapy. Several types of targeted therapy that may be of benefit to clear cell sarcoma patients are currently under investigation.
HGPIN in isolation does not require treatment. In prostate biopsies it is not predictive of prostate cancer in one year if the prostate was well-sampled, i.e. if there were 8 or more cores.
The exact timing of repeat biopsies remains an area of controversy, as the time required for, and probability of HGPIN transformations to prostate cancer are not well understood.
Tamoxifen, a selective estrogen receptor modulator (SERM) with antiestrogenic actions in breast tissue and estrogenic actions in bone, has been found to be highly effective in preventing and reversing bicalutamide-induced gynecomastia in men. Moreover, in contrast to analogues (which also alleviate bicalutamide-induced gynecomastia), tamoxifen poses minimal risk of accelerated bone loss and osteoporosis. For reasons that are unclear, anastrozole, an aromatase inhibitor (or an inhibitor of estrogen biosynthesis), has been found to be much less effective in comparison to tamoxifen for treating bicalutamide-induced gynecomastia. A systematic review of -induced gynecomastia and breast tenderness concluded that tamoxifen (10–20 mg/day) and radiotherapy could effectively manage the side effect without relevant adverse effects, though with tamoxifen showing superior effectiveness. Surgical breast reduction may also be employed to correct bicalutamide-induced gynecomastia.
The Stehlin Foundation currently offers DSRCT patients the opportunity to send samples of their tumors free of charge for testing. Research scientists are growing the samples on nude mice and testing various chemical agents to find which are most effective against the individual's tumor.
Patients with advanced DSRCT may qualify to participate in clinical trials that are researching new drugs to treat the disease.
Combination of bicalutamide with medical (i.e., a analogue) or surgical castration modifies the side effect profile of bicalutamide. Some of its side effects, including breast pain/tenderness and gynecomastia, are far less likely to occur when the drug is combined with a analogue, while certain other side effects, including hot flashes, depression, fatigue, and sexual dysfunction, occur much more frequently in combination with a analogue. It is thought that this is due to the suppression of estrogen levels (in addition to androgen levels) by analogues, as estrogen may compensate for various negative central effects of androgen deprivation. If bicalutamide is combined with a analogue or surgical castration, the elevation of androgen and estrogen levels in men caused by bicalutamide will be prevented and the side effects of excessive estrogens, namely gynecomastia, will be reduced. However, due to the loss of estrogen, bone loss will accelerate and the risk of osteoporosis developing with long-term therapy will increase.
Over the past two decades, CT guided radiofrequency ablation has emerged as a less invasive alternative to surgical resection in the care of benign bone tumors, most notably osteoid osteomas. In this technique, which can be performed under conscious sedation, a RF probe is introduced into the tumor nidus through a cannulated needle under CT guidance and heat is applied locally to destroy tumor cells. Since the procedure was first introduced for the treatment of osteoid osteomas in the early 1990s, it has been shown in numerous studies to be less invasive and expensive, to result in less bone destruction and to have equivalent safety and efficacy to surgical techniques, with 66 to 96% of patients reporting freedom from symptoms. While initial success rates with RFA are high, symptom recurrence after RFA treatment has been reported, with some studies demonstrating a recurrence rate similar to that of surgical treatment.
Thermal ablation techniques are also increasingly being used in the palliative treatment of painful metastatic bone disease. Currently, external beam radiation therapy is the standard of care for patients with localized bone pain due to metastatic disease. Although the majority of patients experience complete or partial relief of pain following radiation therapy, the effect is not immediate and has been shown in some studies to be transient in more than half of patients. For patients who are not eligible or do not respond to traditional therapies ( i.e. radiation therapy, chemotherapy, palliative surgery, bisphosphonates or analgesic medications), thermal ablation techniques have been explored as alternatives for pain reduction. Several multi-center clinical trials studying the efficacy of RFA in the treatment of moderate to severe pain in patients with metastatic bone disease have shown significant decreases in patient reported pain after treatment. These studies are limited however to patients with one or two metastatic sites; pain from multiple tumors can be difficult to localize for directed therapy. More recently, cryoablation has also been explored as a potentially effective alternative as the area of destruction created by this technique can be monitored more effectively by CT than RFA, a potential advantage when treating tumors adjacent to critical structures.
Almost all patients require multidrug chemotherapy (often including ifosfamide and etoposide), as well as local disease control with surgery and/or radiation. An aggressive approach is necessary because almost all patients with apparently localized disease at the time of diagnosis actually have asymptomatic metastatic disease.
Treatment often consists of neoadjuvant chemotherapy, which may include vincristine, doxorubicin, and cyclophosphamide with ifosfamide and etoposide. After about three months of chemotherapy, the remaining tumor is surgically resected, irradiated, or both. The surgical resection may involve limb salvage or amputation. Complete excision at the time of biopsy may be performed if malignancy is confirmed at the time it is examined.
Treatment lengths vary depending on location and stage of the disease at diagnosis. Radical chemotherapy may be as short as six treatments at 3-week cycles, but most patients undergo chemotherapy for 6–12 months and radiation therapy for 5–8 weeks.
Radiotherapy has been used for localized disease. The tumor has a unique property of being highly sensitive to radiation, sometimes acknowledged by the phrase "melting like snow", but the main drawback is that it recurs dramatically after some time. Antisense oligodeoxynucleotides have been proposed as possible treatment by down-regulating the expression of the oncogenic fusion protein associated with the development of Ewing's sarcoma resulting from the EWS-ETS gene translocation. In addition, the synthetic retinoid derivative fenretinide (4-hydroxy(phenyl)retinamide) has been reported to induce high levels of cell death in Ewing's sarcoma cell lines "in vitro" and to delay growth of xenografts in "in vivo" mouse models.
The prognosis for DSRCT remains poor. Prognosis depends upon the stage of the cancer. Because the disease can be misdiagnosed or remain undetected, tumors frequently grow large within the abdomen and metastasize or seed to other parts of the body.
There is no known organ or area of origin. DSRCT can metastasize through lymph nodes or the blood stream. Sites of metastasis include the spleen, diaphragm, liver, large and small intestine, lungs, central nervous system, bones, uterus, bladder, genitals, abdominal cavity, and the brain.
A multi-modality approach of high-dose chemotherapy, aggressive surgical resection, radiation, and stem cell rescue improves survival for some patients. Reports have indicated that patients will initially respond to first line chemotherapy and treatment but that relapse is common.
Some patients in remission or with inoperable tumor seem to benefit from long term low dose chemotherapy, turning DSRCT into a chronic disease.
One of the major concerns is bone density and bone loss. Non-hormonal bisphosphonates increase bone strength and are available as once-a-week prescription pills. Metastron also known as strontium-89 chloride is an intravenous medication given to help with the pain and can be given in three month intervals. Generic Strontium Chloride Sr-89 Injection UPS, manufactured by Bio-Nucleonics Inc., it is the generic version of Metastron. Astra zantec is currently under review as to the benefits in bone cancer.
The disease used to be uniformly fatal, with a 5-year survival rate between 10 and 35%. As a result, treatment was radical surgery. New multidrug chemotherapy regimens with or without radiation therapy are now used in combination with less radical surgery with good results, although outcome data are not yet available.
Surgery is important in the treatment of most sarcomas. Limb sparing surgery, as opposed to amputation, can now be used to save the limbs of patients in at least 90% of extremity tumor cases. Additional treatments, including chemotherapy and radiation therapy, may be administered before and/or after surgery. Chemotherapy significantly improves the prognosis for many sarcoma patients, especially those with bone sarcomas. Treatment can be a long and arduous process, lasting about a year for many patients.
- Liposarcoma treatment consists of surgical resection, with chemotherapy not being used outside of the investigative setting. Adjuvant radiotherapy may also be used after surgical excision for liposarcoma.
- Rhabdomyosarcoma is treated with surgery, radiotherapy, and/or chemotherapy. The majority of rhabdomyosarcoma patients have a 50–85% survival rate.
- Osteosarcoma is treated with surgical resection of as much of the cancer as possible, often along with neoadjuvant chemotherapy. Radiotherapy is a second alternative although not as successful.