Is there any data available regarding the benefit of adjuvant chemotherapy in patients with early stage, lymph node negative, triple negative adenosquamous breast cancers?

Except for a rare low-grade adenosquamous carcinoma, which, according to UpToDate (Taqhian A, Merajver S. Overview of the treatment of newly diagnosed, non-metastatic breast cancer - Rare histologies — Certain very rare subtypes of metaplastic carcinoma (eg, low-grade adenosquamous and low-grade fibromatosis-like carcinoma), have a favorable prognosis without adjuvant systemic therapies. Patients with tumors of such histologies may be offered observation rather than adjuvant systemic therapies, provided that the favorable histologic type is pure (>90 percent as classified on the surgical excision, not core biopsy alone). The critical step in the evaluation of such tumors, because of their rarity, is pathologic review by a highly experienced...