Surgery remains the front-line therapy for HNPCC. There is an ongoing controversy over the benefit of 5-fluorouracil-based adjuvant therapies for HNPCC-related colorectal tumours, particularly those in stages I and II.

Immunohistochemistry is now being used more often to diagnose patients likely to have Muir–Torre syndrome. Sebaceous neoplasms are only infrequently encountered, and immunohistochemistry is reliable and readily available, so researchers have recommended its use. Routine immunohistochemical detection of DNA mismatch repair proteins help identify hereditary DNA mismatch repair deficiency.

Treatment of Muir–Torre syndrome normally consists of oral isotretinoin. The drug has been found to prevent tumor development.

Patients with Muir–Torre syndrome should follow the same stringent screening for colorectal carcinoma and other malignancies as patients with Lynch syndrome. This includes frequent and early colonoscopies, mammograms, dermatologic evaluation, and imaging of the abdomen and pelvis.

Adjuvant chemotherapy is a recent innovation, consisting of some combination of paclitaxel (or other taxanes like docetaxel), doxorubicin (and other anthracyclines), and platins (particularly cisplatin and carboplatin). Adjuvant chemotherapy has been found to increase survival in stage III and IV cancer more than added radiotherapy. Mutations in mismatch repair genes, like those found in Lynch syndrome, can lead to resistance against platins, meaning that chemotherapy with platins is ineffective in people with these mutations. Side effects of chemotherapy are common. These include hair loss, low neutrophil levels in the blood, and gastrointestinal problems.

In cases where surgery is not indicated, palliative chemotherapy is an option; higher-dose chemotherapy is associated with longer survival. Palliative chemotherapy, particularly using capecitabine and gemcitabine, is also often used to treat recurrent endometrial cancer.

The majority of cases of cholangiocarcinoma present as inoperable (unresectable) disease in which case patients are generally treated with palliative chemotherapy, with or without radiotherapy. Chemotherapy has been shown in a randomized controlled trial to improve quality of life and extend survival in patients with inoperable cholangiocarcinoma. There is no single chemotherapy regimen which is universally used, and enrollment in clinical trials is often recommended when possible. Chemotherapy agents used to treat cholangiocarcinoma include 5-fluorouracil with leucovorin, gemcitabine as a single agent, or gemcitabine plus cisplatin, irinotecan, or capecitabine. A small pilot study suggested possible benefit from the tyrosine kinase inhibitor erlotinib in patients with advanced cholangiocarcinoma.

There are a number of possible additional therapies. Surgery can be followed by radiation therapy and/or chemotherapy in cases of high-risk or high-grade cancers. This is called adjuvant therapy.

If the tumor can be removed surgically, patients may receive adjuvant chemotherapy or radiation therapy after the operation to improve the chances of cure. If the tissue margins are negative (i.e. the tumor has been totally ), adjuvant therapy is of uncertain benefit. Both positive and negative results have been reported with adjuvant radiation therapy in this setting, and no prospective randomized controlled trials have been conducted as of March 2007. Adjuvant chemotherapy appears to be ineffective in patients with completely resected tumors. The role of combined chemoradiotherapy in this setting is unclear. However, if the tumor tissue margins are positive, indicating that the tumor was not completely removed via surgery, then adjuvant therapy with radiation and possibly chemotherapy is generally recommended based on the available data.

Hormone therapies are a topic of current research in ovarian cancer, particularly, the value of certain medications used to treat breast cancer. These include tamoxifen, letrozole, and anastrozole. Preliminary studies have showed a benefit for tamoxifen in a small number of people with advanced ovarian cancer. Letrozole may help to slow or stop growth of estrogen receptor positive ovarian cancer. Anastrozole is being investigated in postmenopausal people with estrogen receptor-positive cancer.

Research into mitigating side effects of ovarian cancer treatment is also ongoing. Radiation fibrosis, the formation of scar tissue in an area treated with radiation, may be relieved with hyperbaric oxygen therapy, but research has not been completed in this area. Treatment of ovarian cancer may also cause people to experience psychiatric difficulties, including depression. Research is ongoing to determine how counseling and psychotherapy can help people who have ovarian cancer during treatment.

Hereditary nonpolyposis colorectal cancer (HNPCC) or Lynch syndrome is an autosomal dominant genetic condition that has a high risk of colon cancer as well as other cancers including endometrial cancer (second most common), ovary, stomach, small intestine, hepatobiliary tract, upper urinary tract, brain, and skin. The increased risk for these cancers is due to inherited mutations that impair DNA mismatch repair. It is a type of cancer syndrome.

If ovarian cancer recurs, it is considered partially platinum-sensitive or platinum-resistant, based on the time since the last recurrence treated with platins: partially platinum-sensitive cancers recurred 6–12 months after last treatment, and platinum-resistant cancers have an interval of less than 6 months. Second-line chemotherapy can be given after the cancer becomes symptomatic, because no difference in survival is seen between treating asymptomatic (elevated CA-125) and symptomatic recurrences.

For platinum-sensitive tumors, platins are the drugs of choice for second-line chemotherapy, in combination with other cytotoxic agents. Regimens include carboplatin combined with pegylated liposomal doxorubicin, gemcitabine, or paclitaxel. Carboplatin-doublet therapy can be combined with paclitaxel for increased efficacy in some cases. Another potential adjuvant therapy for platinum-sensitive recurrences is olaparib, which may improve progression-free survival but has not been shown to improve overall survival. (Olaparib, a PARP inhibitor, was approved by the US FDA for use in BRCA-associated ovarian cancer that had previously been treated with chemotherapy.) For recurrent germ cell tumors, an additional 4 cycles of BEP chemotherapy is the first-line treatment for those tho have been treated with surgery or platins.

If the tumor is determined to be platinum-resistant, vincristine, dactinomycin, and cyclophosphamide (VAC) or some combination of paclitaxel, gemcitabine, and oxaliplatin may be used as a second-line therapy.

For platinum-resistant tumors, there are no high-efficacy chemotherapy options. Single-drug regimens (doxorubicin or topotecan) do not have high response rates, but single-drug regimens of topotecan, pegylated liposomal doxorubicin, or gemcitabine are used in some cases. Topotecan cannot be used in people with an intestinal blockage. Paclitaxel used alone is another possible regimen, or it may be combined with liposomal doxorubicin, gemcitabine, cisplatin, topotecan, etoposide, or cyclophosphamide. ( See also Palliative care below.)

There are several different surgical techniques for the removal of acoustic neuroma. The choice of approach is determined by size of the tumour, hearing capability, and general clinical condition of the patient.

- The retrosigmoid approach offers some opportunity for the retention of hearing.

- The translabyrinthine approach will sacrifice hearing on that side, but will usually spare the facial nerve. Post-operative cerebrospinal fluid leaks are more common.

- The middle fossa approach is preferred for small tumours, and offers the highest probability of retention of hearing and vestibular function.

- Less invasive endoscopic techniques have been done outside of the United States for some time. Recovery times are reported to be faster. However, this technique is not yet mainstream among surgeons in the US.

Larger tumors can be treated by either the translabyrinthine approach or the retrosigmoid approach, depending upon the experience of the surgical team. With large tumors, the chance of hearing preservation is small with any approach. When hearing is already poor, the translabyrinthine approach may be used for even small tumors. Small, lateralized tumours in patients with good hearing should have the middle fossa approach. When the location of the tumour is more medial a retrosigmoid approach may be better.

Auditory canal decompression is another surgical technique that can prolong usable hearing when a vestibular schwannoma has grown too large to remove without damage to the cochlear nerve. In the IAC (internal auditory canal) decompression, a middle fossa approach is employed to expose the bony roof of the IAC without any attempt to remove the tumor. The bone overlying the acoustic nerve is removed, allowing the tumour to expand upward into the middle cranial fossa. In this way, pressure on the cochlear nerve is relieved, reducing the risk of further hearing loss from direct compression or obstruction of vascular supply to the nerve.

Radiosurgery is a conservative alternative to cranial base or other intracranial surgery. With conformal radiosurgical techniques, therapeutic radiation focused on the tumour, sparing exposure to surrounding normal tissues. Although radiosurgery can seldom completely destroy a tumor, it can often arrest its growth or reduce its size. While radiation is less immediately damaging than conventional surgery, it incurs a higher risk of subsequent malignant change in the irradiated tissues, and this risk in higher in NF2 than in sporadic (non-NF2) lesions.

Muir–Torre was observed to occur in 14 of 50 families (28%) and in 14 of 152 individuals (9.2%) with Lynch syndrome, also known as HNPCC.

The 2 major MMR proteins involved are hMLH1 and hMSH2. Approximately 70% of tumors associated with the MTS have microsatellite instability. While germline disruption of hMLH1 and hMSH2 is evenly distributed in HNPCC, disruption of hMSH2 is seen in greater than 90% of MTS patients.

Gastrointestinal and genitourinary cancers are the most common internal malignancies. Colorectal cancer is the most common visceral neoplasm in Muir–Torre syndrome patients.

A 2009 clinical trial at Massachusetts General Hospital used the cancer drug Bevacizumab (commercial name: Avastin) to treat 10 patients with neurofibromatosis type II. The result was published in "The New England Journal of Medicine". Of the ten patients treated with bevacizumab, tumours shrank in 9 of them, with the median best response rate of 26%. Hearing improved in some of the patients, but improvements were not strongly correlated with tumour shrinkage. Bevacizumab works by cutting the blood supply to the tumours and thus depriving them of their growth vector. Side effects during the study included alanine aminotransferase, proteinuria, and hypertension (elevated blood pressure) among others. A separate trial, published in "The Neuro-oncology Journal", show 40% tumour reduction in the two patients with NF2, along with significant hearing improvement.

Overall the researchers believed that bevacizumab showed clinically significant effects on NF-2 patients. However, more research is needed before the full effects of bevacizumab can be established in NF-2 patients.

There is currently no treatment or cure for Waardenburg syndrome. The symptom most likely to be of practical importance is deafness, and this is treated as any other irreversible deafness would be. In marked cases there may be cosmetic issues. Other abnormalities (neurological, structural, Hirschsprung disease) associated with the syndrome are treated symptomatically.

Treatment of cause: Due to the genetic cause, no treatment of the cause is possible.

Treatment of manifestations: routine treatment of ophthalmologic, cardiac, and neurologic findings; speech, occupational, and physical therapies as appropriate; specialized learning programs to meet individual needs; antiepileptic drugs or antipsychotic medications as needed.

Surveillance: routine pediatric care; routine developmental assessments; monitoring of specific identified medical issues.

A cancer syndrome or family cancer syndrome is a genetic disorder in which inherited genetic mutations in one or more genes predispose the affected individuals to the development of cancers and may also cause the early onset of these cancers. Cancer syndromes often show not only a high lifetime risk of developing cancer, but also the development of multiple independent primary tumors. Many of these syndromes are caused by mutations in tumor suppressor genes, genes that are involved in protecting the cell from turning cancerous. Other genes that may be affected are DNA repair genes, oncogenes and genes involved in the production of blood vessels (angiogenesis). Common examples of inherited cancer syndromes are hereditary breast-ovarian cancer syndrome and hereditary non-polyposis colon cancer (Lynch syndrome).

Resection is sometimes a part of a treatment plan, but duodenal cancer is difficult to remove surgically because of the area that it resides in—there are many blood vessels supplying the lower body. Chemotherapy is sometimes used to try to shrink the cancerous mass. Other times intestinal bypass surgery is tried to reroute the stomach to intestine connection around the blockage.

A 'Whipple' procedure is a type of surgery that is sometimes possible with this cancer. In this procedure, the duodenum, a portion of the Pancreas (the head), and the gall bladder are usually removed, the small intestine is brought up to the Pylorus (the valve at the bottom of the stomach) and the Liver and Pancreas digestive enzymes and bile are connected to the small intestine below the Pylorus.

The removal of part of the Pancreas often requires taking Pancreatic Enzyme supplements to aid digestion. These are available in the form of capsules by prescription.

It is not unusual for a patient having received a Whipple procedure to feel perfectly well, and to lead his/her normal life without difficulty.

It is important for the procedure to be performed by a surgeon with extensive experience having done and observed the procedure, as specific competence makes a big difference.

Some patients need to be fitted with tubes to either add nutrients (feeding tubes) or drainage tubes to remove excess processed food that can not pass the blockage.

Hereditary cancer syndromes underlie 5 to 10% of all cancers. Scientific understanding of cancer susceptibility syndromes is actively expanding: additional syndromes are being found, the underlying biology is becoming clearer, and commercialization of diagnostic genetics methodology is improving clinical access. Given the prevalence of breast and colon cancer, the most widely recognized syndromes include hereditary breast-ovarian cancer syndrome (HBOC) and hereditary non-polyposis colon cancer (HNPCC, Lynch syndrome).

Some rare cancers are strongly associated with hereditary cancer predisposition syndromes. Genetic testing should be considered with adrenocortical carcinoma; carcinoid tumors; diffuse gastric cancer; fallopian tube/primary peritoneal cancer; leiomyosarcoma; medullary thyroid cancer; paraganglioma/pheochromocytoma; renal cell carcinoma of chromophobe, hybrid oncocytic, or oncocytoma histology; sebaceous carcinoma; and sex cord tumors with annular tubules. Primary care physicians can identify people who are at risk of heridatary cancer syndrome.

The only curative treatment is complete surgical excision of the tumor, which can be performed even in the case of invasion into large blood vessels, such as the renal vein or inferior vena cava. The 5-year survival rate after successful surgery is 50–60%, but unfortunately, a large percentage of patients are not surgical candidates. Radiation therapy and radiofrequency ablation may be used for palliation in patients who are not surgical candidates.

Chemotherapy regimens typically include the drug mitotane, an inhibitor of steroid synthesis which is toxic to cells of the adrenal cortex, as well as standard cytotoxic drugs. A retrospective analysis showed a survival benefit for mitotane in addition to surgery when compared to surgery alone.

The two most common regimens are cisplatin, doxorubicin, etoposide + mitotane and streptozotocin + mitotane. It is unknown which regimen is better. Researchers at Uppsala University Hospital initiated a collaboration between adrenocortical cancer specialists in Europe, USA and Australia, to conduct the first ever randomized controlled trial in adrenocortical cancer (FIRM-ACT study), comparing these two regimens.

Since the symptoms caused by this disease are present at birth, there is no “cure.” The best cure that scientists are researching is awareness and genetic testing to determine risk factors and increase knowledgeable family planning. Prevention is the only option at this point in time for a cure.

Mismatch repair cancer syndrome (MMRCS) is a cancer syndrome associated with biallelic DNA mismatch repair mutations. It is also known as Turcot syndrome (after Jacques Turcot, who described the condition in 1959) and by several other names.

In MMRCS, neoplasia typically occurs in both the gut and the central nervous system (CNS). In the large intestine, familial adenomatous polyposis occurs; in the CNS, brain tumors.

Many professionals that are likely to be involved in the treatment of those with Stickler's syndrome, include anesthesiologists, oral and maxillofacial surgeons; craniofacial surgeons; ear, nose, and throat specialists, ophthalmologists, optometrists, audiologists, speech pathologists, physical therapists and rheumatologists.

Treatment for Klippel–Feil syndrome is symptomatic and may include surgery to relieve cervical or craniocervical instability and constriction of the spinal cord, and to correct scoliosis.

Failing non-surgical therapies, spinal surgery may provide relief. Adjacent segment disease and scoliosis are two examples of common symptoms associated with Klippel–Feil syndrome, and they may be treated surgically. The three categories treated for types of spinal cord deficiencies are massive fusion of the cervical spine (Type I), the fusion of 1 or 2 vertebrae (Type II), and the presence of thoracic and lumbar spine anomalies in association with type I or type II Klippel–Feil syndrome (Type III).

Adjacent segment disease can be addressed by performing cervical disc arthroplasty using a device such as the Bryan cervical disc prosthesis.

The option of the surgery is to maintain range of motion and attenuate the rate of adjacent segment disease advancement without fusion.

Another type of arthroplasty that is becoming an alternate choice to spinal fusion is Total Disc Replacement. Total disc replacement objective is to reduce pain or eradicate it.

Spinal fusion is commonly used to correct spinal deformities such as scoliosis. Arthrodesis is the last resort in pain relieving procedures, usually when arthroplasties fail.

Simple cholecystectomy is suitable for type I patients. For types II–IV, subtotal cholecystectomy can be performed to avoid damage to the main bile ducts. Cholecystectomy and bilioenteric anastomosis may be required. Roux-en-Y hepaticojejunostomy has shown good outcome in some studies.

The cancerous mass tends to block food from getting to the small intestine. If food cannot get to the intestines, it will cause pain, acid reflux, and weight loss because the food cannot get to where it is supposed to be processed and absorbed by the body.

Patients with duodenal cancer may experience abdominal pain, weight loss, nausea, vomiting, and chronic GI bleeding.

Treatments exist for the various symptoms associated with XXXY syndrome. Testosterone therapy, which is giving affected individuals doses of testosterone on a regular basis, has been shown to reduce aggressive behavior in these patients. But, this therapy has also been associated with negative side effects: worsening of behavior, and osteoporosis. Not all individuals are applicable for testosterone therapy, as the best results are often achieved when dosage begins at the initiation of puberty, and these individuals are often diagnosed at a later age, or not at all. Testosterone therapy has been shown to have no positive effect on fertility.

Consideration of the psychological phenotype of individuals with XXXY should be taken into account when treating these patients, because these traits affect compliance with treatments. When caught early, Taurodontism can be treated with a root canal and is often successful. Appropriate planning to avoid Taurodontism is possible, but this syndrome must be diagnosed early, which is not common. Taurodontism can often be detected as a symptom of XXXY syndrome before other characteristics develop, and can be an early indicator for it. Surgical treatments to correct joint problems, such as hip dysplasia are common, and are often successful alongside physiotherapy.

Those with XXXY syndrome can also attend speech therapy. This form of therapy helps patients to understand and produce more complex language. Those with XXXY syndrome tend to experience more severe speech delays, so this form of treatment can be very beneficial to them, and can help them to communicate better with other people.

Since hypotonia is common in those with this syndrome, physical therapy can also be helpful. This form of therapy may help these individuals develop muscle tone, and increase balance and coordination.