Adjuvant therapies for special types of breast cancer.

Recent developments in the adjuvant treatment of breast cancer include an increasing attention to systemic therapies prescribed in homogeneous groups of patients according to the higher chance of benefit. A clear consequence of the current adjuvant treatment strategy is the importance of accurate and reliable histopathological assessment. A proper pathological evaluation may effectively support the definition of prognosis and treatment choice in niches of patients diagnosed with special types of breast cancer. Through the identification of special types of breast cancer, that account for up to 25% of all invasive breast carcinomas, it is possible to select patients with a very good prognosis often close to that of the general population (e.g. tubular and pure cribriform carcinoma). Other features, such as those related with invasive classical lobular carcinoma, might have important correlates of responsiveness to therapy other than indicators of outcome. It was in fact demonstrated that the response to primary chemotherapy is significantly lower in invasive lobular carcinoma, if compared with the ductal histotype. However, the use of available information on special types of breast cancer has been limited in tailoring adjuvant therapy, owing to the absence of standardized criteria and partial reproducibility for diagnosis. Moreover, due to the relative rarity of the disease a large number of features that identify for special types of breast carcinomas have today no particular correlation with the prognosis, and limited data are available on the biology of a large number of breast cancer subtypes. The development of more effective therapies for patients with special types of breast cancer requires tailored treatment investigations through international cooperation and should not rely on information predominantly contributed from small retrospective analyses. Examination of patterns of relapse and treatment response within subpopulations in multiple randomized trials is also mandatory to make progress and reach consensus on how to treat individual patients with special types of breast cancer.