There are different opinions on the best treatment of DCIS. Surgical removal, with or without additional radiation therapy or tamoxifen, is the recommended treatment for DCIS by the National Cancer Institute. Surgery may be either a breast-conserving lumpectomy or a mastectomy (complete or partial removal of the affected breast). If a lumpectomy is used it is often combined with radiation therapy. Tamoxifen may be used as hormonal therapy if the cells show estrogen receptor positivity. Chemotherapy is not needed for DCIS since the disease is noninvasive.

While surgery reduces the risk of subsequent cancer, many people never develop cancer even without treatment and there associated side effects. There is no evidence comparing surgery with watchful waiting and some feel watchful waiting may be a reasonable option in certain cases.

Use of radiation therapy after lumpectomy provides equivalent survival rates to mastectomy, although there is a slightly higher risk of recurrent disease in the same breast in the form of further DCIS or invasive breast cancer. Systematic reviews (including a Cochrane review) indicate that the addition of radiation therapy to lumpectomy reduces recurrence of DCIS or later onset of invasive breast cancer in comparison with breast-conserving surgery alone, without affecting mortality. The Cochrane review did not find any evidence that the radiation therapy had any long-term toxic effects. While the authors caution that longer follow-up will be required before a definitive conclusion can be reached regarding long-term toxicity, they point out that ongoing technical improvements should further restrict radiation exposure in healthy tissues. They do recommend that comprehensive information on potential side effects is given to women who receive this treatment. The addition of radiation therapy to lumpectomy appears to reduce the risk of local recurrence to approximately 12%, of which approximately half will be DCIS and half will be invasive breast cancer; the risk of recurrence is 1% for women undergoing mastectomy.

Surgical removal of the lesion is the first choice of treatment for many clinicians. However, the efficacy of this treatment modality cannot be assessed due to insufficient available evidence. This can be carried out by traditional surgical excision with a scalpel, with lasers, or with eletrocautery or cryotherapy. Often if biopsy demonstrates moderate or severe dysplasia then the decision to excise them is taken more readily. Sometimes white patches are too large to remove completely and instead they are monitored closely. Even if the lesion is completely removed, long term review is still usually indicated since leukoplakia can recur, especially if predisposing factors such as smoking are not stopped.

Many different topical and systemic medications have been studied, including anti-inflammatories, antimycotics (target Candida species), carotenoids (precursors to vitamin A, e.g. beta carotene), retinoids (drugs similar to vitamin A), and cytotoxics, but none have evidence that they prevent malignant transformation in an area of leukoplakia.Vitamins C and E have also been studied with regards a therapy for leukoplakia. Some of this research is carried out based upon the hypothesis that antioxidant nutrients, vitamins and cell growth suppressor proteins (e.g. p53) are antagonistic to oncogenesis. High doses of retinoids may cause toxic effects. Other treatments that have been studied include photodynamic therapy.

Most fibroadenomas are simply monitored. Some are treated by surgical excision. They are removed with a small margin of normal breast tissue if the preoperative clinical investigations are suggestive of the necessity of this procedure. A small amount of normal tissue must be removed in case the lesion turns out to be a phyllodes tumour on microscopic examination.

Because needle biopsy is often a reliable diagnostic investigation, some doctors may decide not to operate to remove the lesion, and instead opt for clinical follow-up to observe the lesion over time using clinical examination and mammography to determine the rate of growth, if any, of the lesion. A growth rate of less than sixteen percent per month in women under fifty years of age, and a growth rate of less than thirteen percent per month in women over fifty years of age have been published as safe growth rates for continued non-operative treatment and clinical observation.

Some fibroadenomas respond to treatment with ormeloxifene.

Fibroadenomas have not been shown to recur following complete excision or transform into phyllodes tumours following partial or incomplete excision.

Nipple adenomas are non-cancerous growths, which can recur if not completely surgically removed. There are reported cases of cancers arising within nipple adenomas, and following excision of nipple adenomas, but these are rare occurrences.

Surgical excision is the standard of care. Some individuals advocate the use of hair removal laser for the treatment of congenital nevi. While this is likely safe and effective for small congenital nevus, laser removal for larger lesions might pose a liability for the laser surgeon if malignancy developed from a deep (dermal) component of the nevus that is not reached by the laser. Repigmentation after laser treatment of congenital nevi or superficial curettage supports this concern.

Many are surgically removed for aesthetics and relief of psychosocial burden, but larger ones are also excised for prevention of cancer, although the benefit is impossible to assess for any individual patient. Proliferative nodules are usually biopsied and are regularly but not systematically found to be benign. Estimates of transformation into melanoma vary from 2-42% in the literature, but are most commonly considered to be at the low end of that spectrum due to early observer bias.

Treatment of invasive carcinoma of no special type (NST) depends on the size of the mass (size of the tumor measured in its longest direction):

- <4 cm mass: surgery to remove the main tumor mass and to sample the lymph nodes in the axilla. The stage of the tumor is ascertained after this first surgery. Adjuvant therapy (i.e., treatment after surgery) may include a combination of chemotherapy, radiotherapy, hormonal therapy (e.g., tamoxifen) and/or targeted therapy (e.g., trastuzumab). More surgery is occasionally needed to complete the removal of the initial tumor or to remove recurrences.

- 4 cm or larger mass: modified (a less aggressive form of radical mastectomy) radical mastectomy (because any malignant mass in excess of 4 cm in size exceeds the criteria for a lumpectomy) along with sampling of the lymph nodes in the axilla.

The treatment options offered to an individual patient are determined by the form, stage and location of the cancer, and also by the age, history of prior disease and general health of the patient. Not all patients are treated the same way.

Carcinoma "in situ" is, by definition, a localized phenomenon, with no potential for metastasis unless it progresses into cancer. Therefore, its removal eliminates the risk of subsequent progression into a life-threatening condition.

Some forms of CIS (e.g., colon polyps and polypoid tumours of the bladder) can be removed using an endoscope, without conventional surgical resection. Dysplasia of the uterine cervix is removed by excision (cutting it out) or by burning with a laser. Bowen's disease of the skin is removed by excision. Other forms require major surgery, the best known being intraductal carcinoma of the breast (also treated with radiotherapy). One of the most dangerous forms of CIS is the "pneumonic form" of BAC of the lung, which can require extensive surgical removal of large parts of the lung. When too large, it often cannot be completely removed, with eventual disease progression and death of the patient.

The primary treatment is surgical. FIGO-cancer staging is done at the time of surgery which consists of peritoneal cytology, total hysterectomy, bilateral salpingo-oophorectomy, pelvic/para-aortic lymphadenectomy, and omentectomy. The tumor is aggressive and spreads quickly into the myometrium and the lymphatic system. Thus even in presumed early stages, lymphadenectomy and omentectomy should be included in the surgical approach. If the tumor has spread surgery is cytoreductive followed by radiation therapy and/or chemotherapy.

In a study to determine if adjuvant therapy should be used in patients with stage I UPSC who had undergone surgery, no increased survival was seen when radiation therapy was added versus observation, while the postsurgical treatment with chemotherapy may be beneficial but more data are needed.

A study of the usefulness of platinum-based chemotherapy as an adjuvant after surgery of stage I patients showed that patients with stage 1A who had no residual disease in the hysterectomy specimen had no recurrence regardless if chemotherapy was used or not, however, patients with stage 1A disease with residual disease in the hysterectomy specimen had no recurrence with platinum-based therapy, but those who had no such chemotherapy showed recurrence in 43%. Similarly, patients with stage 1B disease with chemotherapy had no recurrence, while those without chemotherapy had a high degree (77%) of recurrence.

Treatment is problematic unless an underlying endocrine disorder can be successfully diagnosed and treated.

A study by Goepel and Panhke provided indications that the inflammation should be controlled by bromocriptine even in absence of hyperprolactinemia.

Antibiotic treatment is given in case of acute inflammation. However, this alone is rarely effective, and the treatment of a subareaolar abscess is primarily surgical. In case of an acute abscess, incision and drainage are performed, followed by antibiotics treatment. However, in contrast to peripheral breast abscess which often resolves after antibiotics and incision and drainage, subareaolar breast abscess has a tendency to recur, often accompanied by the formation of fistulas leading from inflammation area to the skin surface. In many cases, in particular in patients with recurrent subareolar abscess, the excision of the affected lactiferous ducts is indicated, together with the excision of any chronic abscess or fistula. This can be performed using radial or circumareolar incision.

There is no universal agreement on what should be the standard way of treating the condition. In a recent review article, antibiotics treatment, ultrasound evaluation and, if fluid is present, ultrasound-guided fine needle aspiration of the abscess with an 18 gauge needle, under saline lavage until clear, has been suggested as initial line of treatment for breast abscess in puerperal and non-puerperal cases including central (subareolar) abscess (see breast abscess for details). Elsewhere, it has been stated that treatment of subareolar abscess is unlikely to work if it does not address the ducts as such.

Duct resection has been traditionally used to treat the condition; the original Hadfield procedure has been improved many times but long term success rate remains poor even for radical surgery. Petersen even suggests that damage caused by previous surgery is a frequent cause of subareolar abscesses. Goepel and Pahnke and other authors recommend performing surgeries only with concomitant bromocriptine treatment.

These lesions rarely require surgery unless they are symptomatic or the diagnosis is in question. Since these lesions do not have malignant potential, long-term observation is unnecessary. Surgery can include the removal of the head of the pancreas (a pancreaticoduodenectomy), removal of the body and tail of the pancreas (a distal pancreatectomy), or rarely removal of the entire pancreas (a total pancreatectomy). In selected cases the surgery can be performed using minimally invasive techniques such as laparoscopy.

ADH, if found on a surgical (excisional) biopsy of a mammographic abnormality, does not require any further treatment, only mammographic follow-up.

If ADH is found on a core (needle) biopsy (a procedure which generally does not excise a suspicious mammographic abnormality), a surgical biopsy, i.e. a breast lumpectomy, to completely excise the abnormality and exclude breast cancer is the typical recommendation.

Treatment:wide excision taking 8mm normal tissue as this is locally malignant. For recurrence radiotherapy is given

The appropriate treatment in contemporary western medicine is complete surgical excision of the abnormal growth with a small amount of normal surrounding breast tissue.

The treatment of choice for main-duct IPMNs is resection due to approximately 50% chance of malignancy. Side-branch IPMNs are occasionally monitored with regular CT or MRIs, but most are eventually resected, with a 30% rate of malignancy in these resected tumors. Survival 5 years after resection of an IPMN without malignancy is approximately 80%, 85% with malignancy but no lymph node spread and 0% with malignancy spreading to lymph nodes. Surgery can include the removal of the head of the pancreas (a pancreaticoduodenectomy), removal of the body and tail of the pancreas (a distal pancreatectomy), or rarely removal of the entire pancreas (a total pancreatectomy). In selected cases the surgery can be performed using minimally invasive techniques such as laparoscopy or robotic surgery. A study using Surveillance, Epidemiology, and End Result Registry (SEER) data suggested that increased lymph node counts harvested during the surgery were associated with better survival in invasive IPMN patients.

The presence of a radial scar on imaging mandates a percutaneous core biopsy for histologic diagnosis. Excisional biopsy is usually recommended for radial scar, although it has been argued that core biopsy evaluation and surveillance may be appropriate in selected patients.

Treatment protocol is not well established. Some sources report that approximately half of the patients will fully recover after lengthy (mean time 14.5 months, range 2–24 months) expectant management.

Treatment with steroids is lengthy and usually requires about 6 months. While some source report very good success with steroids most report a considerable risk of recurrence after a treatment with steroids alone. Steroids are known to cause elevation of prolactin levels and increase risk of several conditions such as diabetes, and other endocrinopathies which in turn increase the risk of IGM. Treatment with topical steroids to limit side effects was also reported in one case. For surgical treatment recurrence rates of 5-50% have been reported.

A 1997 literature review article recommended complete resection or corticosteroid therapy, stating also that long-term follow-up was indicated due to a high rate of recurrence.

Treatment with a combination of glucocorticoids and prolactin lowering medications such as bromocriptine or cabergoline was used with good success in Germany. Prolactin lowering medication has also been reported to reduce the risk of recurrence. In cases of drug-induced hyperprolactinemia (such as antipsychotics) prolactin-sparing medication can be tried.

Methotrexate alone or in combination with steroids has been used with good success. Its principal mechanism of action is immunomodulating activity, with a side effect profile that is more favorable for treating IGM.

Colchicine, azathioprine and NSAIDs have also been used.

The initial approach to tubal cancer is generally surgical and similar to that of ovarian cancer. As the lesion will spread first to the adjacent uterus and ovary, a total abdominal hysterectomy is an essential part of this approach and removes the ovaries, the tubes, and the uterus with the cervix. Also, peritoneal washings are taken, the omentum is removed, and pelvic and paraaortic lymph nodes are sampled. Staging at the time of surgery and pathological findings will determine further steps. In advanced cases when the cancer has spread to other organs and cannot be completely removed cytoreductive surgery is used to lessen the tumor burden for subsequent treatments. Surgical treatments are typically followed by adjuvant usually platinum-based chemotherapy.

Also radiation therapy has been applied with some success to patients with tubal cancer for palliative or curative indications

The FDA has approved cryoablation of a fibroadenoma as a safe, effective and minimally-invasive alternative to open surgical removal in 2001. In the procedure, ultrasound imaging is used to guide a probe into the mass of breast tissue. Extremely cold temperatures are then used to destroy the abnormal cells, and over time the cells are reabsorbed into the body. The procedure can be performed as an outpatient surgery using local anesthesia only, and leaves substantially less scarring than open surgical procedures and no breast tissue deformation.

The American Society of Breast Surgeons recommends the following criteria to establish a patient as a candidate for cryoablation of a fibroadenoma:

1. The lesion must be sonographically visible.

2. The diagnosis of a fibroadenoma must be confirmed histologically.

3. The lesion should be less than 4 cm in diameter.

Most women with fibrocystic changes and no symptoms do not need treatment, but closer follow-up may be advised.

There is no widely accepted treatment or prevention strategy for fibrocystic condition. When treatment of symptoms is necessary it follows the same strategies as treatment for cyclical breast pain.

It is controversial whether benign breast conditions improve or worsen with oral contraceptives or hormone replacement therapy.

A few small-scale studies have indicated that the fibrocystic condition may be improved by dietary changes (especially by a reduced intake of caffeine and related methylxanthines or by a reduced intake of salt) and by vitamin supplements.

Small, preliminary studies have shown beneficial effects of iodine supplementation (such as reducing the presence of breast cysts, fibrous tissue plaques and breast pain) in women with fibrocystic breast changes, with elemental iodine (I) being more effective than iodide (I). It is noted that iodine supplementation, via an iodine-based modulation of estrogen influence in the breast, also appears to inhibit early cancer progression in small studies done on breast cancer cells in a lab.. Since treatment success in a lab is often not replicated in humans, more human research is necessary to determine if iodine supplementation prevents breast cancer

A U.S. National Institutes of Health fact sheet of 2011 reported on a randomized, double-blind, placebo-controlled clinical trial performed on 111 women affected by fibrosis and having a history of breast pain. In this trial, daily doses of iodine led to decreased in breast pain, tenderness and nodularity. It was emphasized that further research to clarify iodine's role in fibrocystic breast disease is needed and that large doses of iodine should only be used under the guidance of a physician.

In a recent study, about 60% of USCs were found to overexpress the protein HER2/neu—the same one that is overexpressed in some breast cancers. The monoclonal antibody trastuzumab (Herceptin) is currently being tested as a therapy for this subset of USCs.

The antibody trastuzumab (Herceptin), which is used to treat breast cancers that overexpress the HER2/neu protein, has been tried with some success in a phase II trial in women with UPSCs that overexpress HER2/neu.

Treatment of metastatic breast cancer is currently an active area of research. Several medications are in development or in phase I/II trials. Typically new medications and treatments are first tested in metastatic cancer before trials in primary cancer are attempted.

Another area of research is finding combination treatments which provide higher efficacy with reduced toxicity and side effects.

Experimental medications:

- sorafenib a combined Tyrosine protein kinases inhibitor.

Chemotherapeutic options include:

- Cyclophosphamide plus methotrexate plus fluorouracil (CMF).

- Cyclophosphamide plus doxorubicin plus fluorouracil (CAF).

- Trastuzumab (monoclonal antibody therapy).

Hormonal options include:

- Orchiectomy.

- Gonadotropin hormone releasing hormone agonist (GNRH agonist) with or without total androgen blockage (anti-androgen).

- Tamoxifen for estrogen receptor–positive patients.

- Progesterone.

- Aromatase inhibitors.

Some patients with metastatic breast cancer opt to try alternative therapies such as vitamin therapy, homeopathic treatments, a macrobiotic diet, chiropractic or acupuncture. There is no evidence that any of these therapies are effective; they may be harmful, either because patients pass up effective conventional therapies such as chemotherapy or anti-estrogen therapy in favor of alternative treatments, or because the treatments themselves are harmful (as in the case of apricot-pit therapy—which exposes the patient to cyanide—or in chiropractic, which can be dangerous to patients with cancer metastatic to the spinal bones or spinal cord. A macrobiotic diet is neither effective nor safe as it could hypothetically induce weight loss due to severe dietary restriction. There is limited evidence that acupuncture might relive pain in cancer patients, but data so far is insufficient to recommend its use outside of clinical trials.

There is free peer support and an online platform to interact with others going through various therapies, including Abraxane.