As noted by Yardley et al in their MBCC poster,1 the lower staging merely means a better overall outlook. “Assignment of a lower stage using the prognostic stage group table does not indicate that a patient can forgo systemic therapy. Instead, it indicates that with appropriate therapy based on both tumor biology and the anatomic extent of disease, the patient has a better prognosis,” the authors wrote.
There are imperfections with the AJCC manual, Mittendorf said. “The pathologic prognostic stage is not applicable to patients receiving neoadjuvant therapy, and there are questions as to how this will be incorporated into the NCCN guidelines, and what is the impact on clinical trials?” She said better clinical data are needed. The NCCN is actively discussing the issue, but their algorithms already are determined by TNM categories and ER, PR, and HER2, “so, in fact, they may not need to make many substantive changes.” As for clinical trials, Mittendorf said there will need to be revisions in staging.
Adherence Data Essential
Another limitation of the eighth manual was noted in a separate poster presentation at MBCC.4
Although biologic indicators contribute to an accurate prognosis, therapy adherence plays a big role, and data should be properly defined, the authors wrote.
They analyzed adherence among a Denver-area population of patients with breast cancer who underwent lumpectomy and intraoperative radiation therapy. Patients (n = 100) were classified using pathological prognostic staging, and noncompliance was documented among 25 (25%) of patients in the series. They included 6 (86%) of 7 patients in the full cohort who experienced locoregional recurrence. “Therapy adherence was an expectation important to the predictive benefit of this group,” the authors wrote.
“Basically [the study] says that this prognostic system isn’t valid if patients are not taking their recommended therapy. The number of recurrences being reported may not truly reflect the picture of what’s going on,” lead author Barbara S. Schwartzberg, MD, president of Western Surgical Care in Denver, said in an interview with OncLive
- Yardley DA, Le-Petros HC, Hronek J, Edelweiss M, Hurwitz S. Major updates to the American Joint Committee on Cancer (AJCC) 8th edition cancer staging manual for breast cancer: clinical implications for medical oncologists. Presented at: the Miami Breast Cancer Conference®, March 8-11, Miami, Florida. Abstract 613.
- Chavez-MacGregor M, Mittendorf EA, Clarke CA, Lichtensztajn DY, Hunt KK, Giordano SH. Incorporating tumor characteristics to the American Joint Committee on Cancer breast cancer staging system. Oncologist. 2017;22(11):1292-1300. doi: 10.1634/theoncologist.2017-0116.
- Sparano JA, Gray RJ, Makower DF, et al. Prospective validation of a 21-gene expression assay in breast cancer. N Engl J Med. 2015;373(21):2005-2014. doi: 10.1056/NEJMoa1510764.
- Schwartzberg BS, Miller SA, Paul D. Prognostic benefit of American Joint Commission on Cancer (AJCC) 8th edition breast cancer pathological prognostic stage group in patients treated with intraoperative radiation therapy (IORT) at a single institution in Denver, Colorado. Presented at: the Miami Breast Cancer Conference®, March 8-11, Miami, Florida. Abstract 627.