Neoadjuvant therapy for breast cancers: Hope for patients with metastatic disease
Breast cancer is the second most common cancer among women. Although most women are diagnosed with early breast cancer, many women will have breast cancer recurrence despite surgery because of persistent microscopic metastatic disease. Hence breast cancer patients are also provided with chemotherapy or systemic adjuvant (‘to aid’ in Latin) chemotherapy, which can target the tiniest of tumour tissue spreads. Chemotherapy has now advanced to newer combinations that provide good results. Adjuvant treatments for breast cancer include chemotherapy, hormonal therapy, radiation, and human epidermal growth factor receptor (HER2)–directed therapies. Radiation can eradicate local microscopic disease that could be present in the breast, chest wall, skin, and nearby lymph nodes. Chemotherapy given as systemic medications, through a vein, has the capacity to kill microscopic disease even those that are far away from breast tissues. Although women had to undergo serious side-effects of these therapies in the past, advancements in adjuvant therapies that have been achieved over the past few years have made these treatments very efficient and tolerable. However, larger tumors require a different approach.
Neoadjuvant therapy, on the other hand, is considered in patients before undergoing surgical treatment for cancer. If the cancers are locally in advanced stages and are inoperable, chemotherapy given before surgery (neo-adjuvant) is adopted as the management option. In breast cancers, neoadjuvant therapy typically includes chemotherapy, while neoadjuvant endocrine therapy is beneficial in certain types of breast cancer. Neoadjuvant therapy is given so that the tumor may reduce in size and the subsequent surgery is less extensive with fewer postsurgical complications. Hormone neoadjuvant therapy is particularly provided to postmenopausal women. In addition, the cosmetic outcome is also better with neoadjuvant therapies and may be considered in women are older in whom chemotherapy cannot be given, or those who wish to have breast-conserving surgery and avoid mastectomy. In many patients neoadjuvant therapy provides enough tumor response to make such surgeries possible.
One school of thought indicates that the delay of surgery by pre-operative therapy could provide potential harm to patients since the tumor may progress during neoadjuvant therapy, particularly with endocrine therapy. But studies have indicated that neoadjuvant chemotherapy successfully reduced both locoregional (local spread) and breast tumor recurrence in large tumors. Recently, with newer cancer research advancements, neoadjuvant therapy can suggest the prognosis of survival in breast cancer patients that can be used as a marker of survival. This can be of great benefit especially in the assessment of metastatic disease.
In conclusion, cancer treatments have come a long way, although many women still suffer from recurrent metastatic disease despite early treatment. Further research should focus on the complex nature of breast cancer and develop tools that can provide therapy to target individual tumors to reduce breast cancer recurrence from metastatic disease. Neoadjuvant chemotherapy appears to be a major step in that direction.