To The Editor
I want to congratulate Dr. Tan and colleagues for their article entitled “Weekly taxane-anthracycline
combination regimen versus tri-weekly anthracycline-based regimen for the treatment
of locally advanced breast cancer: a randomized controlled trial” [1]. The pathologic
complete response (pCR) rate was similar in the two arms (10.61% vs. 12.31%, P = 0.665).
However, the authors did not stratify patients according to molecular subtypes such
as luminal A and B, human epidermal growth factor receptor 2 (HER2)-positive and triple-negative
breast cancers (TNBC). Rouzier et al. [2] reported that the patients in TNBC and HER2-positive
subgroups had the highest rates of pCR (45% and 45%), whereas the patients with luminal
tumors had a pCR rate of 6% after neoadjuvant chemotherapy. Since HER2-positive and
TNBC subgroups of tumors are more sensitive to chemotherapy, pCR rates in these tumors
are expected to be more than 20%–25%. Taken all together, the evaluation of pCR rates
after chemotherapy in locally advanced breast cancer patients would be better evaluated
according to molecular subtypes.
I confirm that I have read BioMed Central’s guidance on competing interests. I have
no competing interests in the manuscript.
References
Tan QW, Luo T, Zheng H, Tian TL, He P, Chen J, et al. Weekly taxane-anthracycline
combination regimen versus tri-weekly anthracycline-based regimen for the treatment
of locally advanced breast cancer: a randomized controlled trial. Chin J Cancer. 2017;
36(1):27.
Rouzier R, Perou CM, Symmans WF, Ibrahim N, Cristofanilli M, Anderson K, et al. Breast
cancer molecular subtypes respond differently to preoperative chemotherapy. Clin Cancer
Res. 2005;11(16):5678–85.
The author and colleagues reply
We thank Dr. Altundag for the letter discussing our recent study [1]. As mentioned
in the Discussion section of our article, hormone receptor (HR)-positive breast cancers
are less sensitive to chemotherapy than HR-negative breast cancers. A subgroup analysis
would have been meaningful for our study. However, as you may notice, some important
information including human epidermal growth factor receptor 2 (HER2) status were
missing. As locally advanced breast cancers are relatively rare in clinical practice,
it would have taken us more than 3 years to enroll 293 eligible women. If we excluded
the patients with missing information, the sample size for subgroup analyses would
have been too small. In addition, limited by the rarity of locally advanced breast
cancers as well, we did not plan for a subgroup analysis during sample size calculations.
Retrospective subgroup analyses in a prospective trial would reduce the test power
and against the principle of statistics.
The pathologic complete response (pCR) rate reported in our study was similar with
some other studies [2, 3]. The majority of patients in the study were HR-positive
(70%), with a HER2-positive rate of less than 50%, which was significanty lower than
those reported by Rouzier et al. [4]. We believe these variations may account for
the overall differences in chemotherapy responses.
Qiu-Wen Tan1, Ting Luo2, Hong Zheng2, Ting-Lun Tian2, Ping He2, Jie Chen1, He-Lin
Zeng2, Qing Lv1*
1 Department of Breast Surgery, West China Hospital, Sichuan University, Chengdu,
Sichuan 610041, P. R. China
2 Department of Medical Oncology, West China Hospital, Sichuan University, Chengdu,
Sichuan, 610041, P. R. China
*Correspondence: lvqingwestchina@163.com
References
Tan QW, Luo T, Zheng H, Tian TL, He P, Chen J, et al. Weekly taxane-anthracycline
combination regimen versus tri-weekly anthracycline-based regimen for the treatment
of locally advanced breast cancer: a randomized controlled trial. Chin J Cancer. 2017;
36(1):27.
de Matteis A, Nuzzo F, D’Aiuto G, Labonia V, Landi G, Rossi E, et al. Docetaxel plus
epidoxorubicin as neoadjuvant treatment in patients with large operable or locally
advanced carcinoma of the breast: a single-center, phase II study. Cancer. 2002;94(4):895–901.
Steger GG, Galid A, Gnant M, Mlineritsch B, Lang A, Tausch C, et al. Pathologic complete
response with six compared with three cycles of neoadjuvant epirubicin plus docetaxel
and granulocyte colony-stimulating factor in operable breast cancer: results of ABCSG-14.
J Clin Oncol. 2007;25(15):2012–8.
Rouzier R, Perou CM, Symmans WF, Ibrahim N, Cristofanilli M, Anderson K, et al. Breast
cancer molecular subtypes respond differently to preoperative chemotherapy. Clin Cancer
Res. 2005;11(16):5678–85.