Index score may help to determine need for further chemotherapy in breast cancer

We are getting better at using molecular methods in the clinic to determine cancer recurrence risk, and need for adjuvant therapy. I find this story to be fascinating as it evolves. One of the tumors which is furthest along is breast cancer. Another new study is coming out on October 1 in the Journal of the National Cancer Institute. Some details of the study are here. You may also be able to view the full text from the link at the bottom of the page if you have a subscription.

Briefly, this is a study of 228 postmenopausal women who received neoadjuvant hormonal therapy, from which the researchers developed a "preoperative endocrine prognostic index" for relapse-free survival or PEPI. The PEPI confirmed at being stage 0 or 1 at surgery, being node negative, having a clinical response, posttreatment Ki-67 level, and having a grade I tumor all predicted for excellent relapse-free survival. PEPI risk score 0 did do the best, and there were significant differences among PEPI scores 0, 1-3 and 4 or more.

These data suggest that there are a cohort of women who have a good response to endocrine therapy who may not require further chemotherapy. Wouldn't that be wonderful, in particular for the older or frailer patients? The editors of the JNCI do point out some important limitations, including that these women received different endocrine therapies, and the impact of which therapy was used is not known, the sample size is small, and the follow-up is relatively short at only five years. I believe this study brings us further down the road towards more individualized recommendations about adjuvant chemotherapy for breast cancer.