more assumptions stood on their ear: pCR after neoadjuvant treatment for her2+ breast

[Lani]

cancer may NOT indicate those with best prognosis in those that are ER+ and (on a different note) it MAY be important whether there is any remaining DCIS after neoadjuvant therapy(which happens more often in her2+ patients):

Does pCR Provide Valid Information About Long-term Outcome in Patients With HER2-Positive Disease?

Recent neoadjuvant studies support consideration of pCR as a reliable surrogate marker for long-term outcome, not only for the effect of chemotherapy but also for the effect of trastuzumab in HER2-positive breast cancer. The NOAH (NeOAdjuvant Herceptin) study demonstrated that trastuzumab in addition to chemotherapy not only doubled pCR rates compared with chemotherapy alone, but it also reduced the relapse rate by half.[5] The TECHNO (Taxol Epirubicin Cyclophosphamide(Drug information on cyclophosphamide) Herceptin Neoadjuvant) study reported a significantly more favorable disease-free and overall survival for patients who achieved a pCR compared with those who did not.[6]
However, a recent pooled analysis of the German neoadjuvant studies investigated whether the prognostic impact of pCR on long-term outcome is equal to that of neoadjuvant chemotherapy and trastuzumab for patients with hormone receptor (HR)-positive and -negative tumors.[7] In fact, whereas in 298 patients with HER2-positive/HR-negative tumors, a pCR was associated with a significantly better disease-free survival compared with no pCR (hazard ratio [HR] = 8.7, P < .001), no difference in outcome was seen in 356 patients with HER2-positive/HR-positive tumors (HR = 1.2; P = .543). Even without having an explanation for this observation, information about pCR should be used with caution in these triple-positive tumors unless other data sets provide different evidence.
Noninvasive disease as the only remaining tumor tissue (ypTis ypN0) after neoadjuvant chemotherapy is a rare event in HER2-negative disease, but it was reported much more frequently in patients with HER2-positive tumors treated with chemotherapy and anti-HER2 agents. In the GeparQuinto study, remaining noninvasive disease was found in 3.4% of HER2-negative patients, but in 14.3% of patients with HER2-positive disease after chemotherapy and trastuzumab.[8,9] Whereas earlier data sets, for example those from The University of Texas MD Anderson Cancer Center, could not indicate a different prognosis for 89 patients with remaining noninvasive disease and 199 patients with no remaining viable tumor cells (ypT0 ypN0),[10] a more recent pooled analysis of the German neoadjuvant studies demonstrated a significant higher relapse rate among 309 patients with noninvasive disease, compared with 955 patients with no remaining viable tumor cells.[2] In fact, the highest HR for disease-free and overall survival in patients with pCR vs without pCR was observed when using this most conservative definition. In clinical practice, therefore, one should not be overly optimistic in informing patients with remaining noninvasive disease about their prognosis.