Pathologic Predictors of Tumor Response to Preoperative Chemotherapy in Locally Advanced Breast Carcinoma

Feasibility of breast conservation after neoadjuvant taxene based chemotherapy in locally advanced breast cancer: a Prospective Phase I trial

BACKGROUND

Neoadjuvant chemotherapy is the standard care for locally advanced breast cancer. Our study aimed at evaluating the feasibility of breast conversation surgery (BCS) after neoadjuvant chemotherapy.

PATIENTS AND METHODS

Forty five patients had stage IIB (except those with T2N1 disease) and stage IIIA were selected to 3 cycles taxane-based neoadjuvant chemotherapy. Patient who had tumours ≤5 cm underwent a tentative BCS while patients who had tumour size >5 cm underwent radical surgery. Negative margin is essential for BCS. Adjuvant chemotherapy and 3-D radiotherapy ± hormonal treatment were given to all patients.

RESULTS

Thirty four patients had BCS. Response to chemotherapy was the only statistically significant factor which influences the BCS. Incidence of local recurrence was 5.9% for patients who had BCS at a median follow up 24 months.

CONCLUSION

Breast conservation is feasible in selected cases of locally advanced, non metastatic cancer breast. We recommend that patients who have tumour size ≤4 cm after chemotherapy are the best candidates for BCS.

Clinical implications of chemotherapy-induced tumor gene expression in human breast cancers

IMPORTANCE OF THE FIELD

There has been much interest in generating gene signatures to predict treatment response in breast cancer.

AREAS COVERED IN THIS REVIEW

There are at least 15 published studies that describe baseline tumor gene signatures predicting chemotherapy sensitivity. As an extension of these baseline studies, there have been at least 8 published studies evaluating chemotherapy-induced tumor genomic changes over time in human breast cancers.

WHAT THE READER WILL GAIN

Studies on chemotherapy-induced gene expression changes were reviewed in detail. Drug-induced biological changes within the tumor shed light on mechanisms of drug resistance and provided valuable insights regarding genes and pathways that were regulated by different drugs, including therapeutic targets that could be exploited to overcome resistance. One study also suggested post-chemotherapy gene signatures to be more predictive of response and survival than the unchallenged baseline signatures.

TAKE HOME MESSAGE

Studies on chemotherapy-induced changes, although informative, are logistically demanding to execute, often with significant attrition of collected samples resulting in small datasets. They are further limited by heterogeneity of study population, chemotherapy regimens used, timing of the post-therapy sample and definition of response endpoint, making cross-comparisons of studies and data interpretation difficult. Future studies should address these limitations, and should involve larger sample sets and prospective studies for validation.

A pilot study to assess the feasibility of evaluation of markers of response to chemotherapy at one day & 21 days after first cycle of chemotherapy in carcinoma of breast: a prospective non-randomized observational study

BACKGROUND

Interest in translational studies aimed at investigating biologic markers in predicting response to primary chemotherapy (PCT) in breast cancer has progressively increased. We conducted a pilot study to evaluate feasibility of evaluating biomarkers of response to PCT at one & 21 days after first cycle.

METHODS

Adult, non-pregnant, non-lactating women with histologically confirmed infiltrating duct carcinoma underwent serial core biopsies after first cycle of PCT and these were scored for Ki-67, Bcl-2 and Caspase-3 using immunohistochemistry.

RESULTS

We recruited 30 patients with a mean age of 51 years. We were successful 95.6% times in performing a core biopsy and of these 84.6% had adequate tissue in the cores harvested. After a mean of 4 cycles of PCT, 26 patients underwent surgery and good response was noted in 9 patients (30%) using Miller-Payne criteria. There was a trend noted in all markers, which appeared different in those with good response and poor response. Good responders had significantly higher Ki-67 and significantly lower Bcl-2 at baseline and a significant decrease in Ki-67 and Caspase-3 at 21 days after the first chemotherapy.

CONCLUSION

We report a detectable change in biomarkers as early as 24-48 hours after the first chemotherapy along with a definite trend in change that can possibly be used to predict response to chemotherapy in an individual patient. The statistical significance and clinical utility of such changes needs to be evaluated and confirmed in larger trials.

High-dose chemotherapy: how resistant is breast cancer?

This report reviews clinical experience with high-dose chemotherapy with stem-cell support in breast cancer and attempts to integrate clinical and molecular biological observations into a model of drug resistance. Despite the remarkable initial chemosensitivity of breast cancer, the majority of patients with advanced breast cancer die of their disease. In trials to date, high-dose chemotherapy has not been able to overcome primary drug resistance and patients with disease progression during induction therapy benefit little from further high-dose therapy. On the other hand, high-dose chemotherapy produces improved objective response rates compared with standard-dose chemotherapy due to converting some partial responses achieved by standard-dose induction therapy to complete response. This suggests that high-dose chemotherapy may overcome partial clinical drug resistance and may result in a more complete elimination of chemosensitive cells. Whether increased complete response rates will translate into higher cure rates and increased overall survival remains to be unequivocally demonstrated. There are multiple clinical patterns of drug failure including continued growth during chemotherapy, partial response followed by a period of stable disease, initial complete response with subsequent recurrence within a few months or after several years. Different mechanisms of drug resistance may operate at different stages of the disease and predispose patients to different clinical patterns of failure. A model of clonal progression of cancer is proposed that could explain several intriguing features of clinical drug resistance. We hypothesize that drug-sensitivity is an acquired characteristic of neoplastic cells and that a 'physiological drug-resistant' state may precede drug sensitivity at early stages of neoplastic transformation. Some recurrences may, in this context, represent progression of physiologically drug-resistant clones to sensitivity and subsequently to 'pathologic resistance' to chemotherapy. Optimal therapy to delay or prevent recurrence may differ depending on the stage and biology of the tumor and may include combinations of cytotoxic drugs and chemopreventive agents to arrest progression of early physiologically drug-resistant neoplastic stem cells.

Technology Insight: emerging techniques to predict response to preoperative chemotherapy in breast cancer

During the past decade, several high-throughput analytical methods have been developed, and most of these are being explored as potential diagnostic tools. Gene expression profiling with DNA microarrays or with multiplex polymerase chain reaction are the methods closest to being of clinical use. Prediction of clinically meaningful response to particular chemotherapy regimens or drugs remains a persistent challenge. There are established clinical and histopathologic predictors of prognosis for breast cancer, but there is no test to assist in selecting the optimal chemotherapy regimen for patients. Here we review recent advances in the application of gene expression profiling to chemotherapy response prediction.

Update on locally advanced breast cancer

Locally advanced breast cancer remains a clinical challenge as the majority of patients with this diagnosis develop distant metastases despite appropriate therapy. Patients with locally advanced disease encompass a wide range of clinical scenarios including advanced primary tumors (stage T4), advanced nodal disease (fixed axillary nodes or involvement of ipsilateral supraclavicular, infraclavicular, or internal mammary nodes), and inflammatory carcinomas. The prognoses of women with locally advanced breast tumors are also heterogeneous and depend on tumor size, extent of lymph node involvement, and the presence or absence of inflammatory carcinoma. Women with locally advanced disease require multimodal therapy, and coordinated treatment planning among the medical oncologist, surgical oncologist, and radiation oncologist is necessary to optimize patient care. In this article, the epidemiology, evaluation, prognostic factors, and treatment for locally advanced breast cancer are discussed. Inflammatory cancer is also reviewed, but is considered separately due to its distinct biology and clinical behavior.

Assessment of histologic features and expression of biomarkers in predicting pathologic response to anthracycline-based neoadjuvant chemotherapy in patients with breast carcinoma

BACKGROUND

There is significant variability in the response of tumors to neoadjuvant chemotherapy, and the underlying mechanism for this variability is unknown. In this study, the authors investigated the roles of tumor nuclear grade, mitotic activity, and biomarker expression profiles in predicting the pathologic response of breast tumors to preoperative chemotherapy.

METHODS

Eighty-two patients with breast carcinoma participated in two clinical trials and were treated with neoadjuvant chemotherapy, which consisted of either a conventional dose of fluorouracil, doxorubicin, and cyclophosphamide (FAC) or dose-escalated FAC. The mean age of the patients was 46 years (range, 24-69 years). Nuclear grade, mitotic activity, and biomarker profile (Her2-neu and mitosin expression patterns) in pretreatment tumors were correlated with the postchemotherapy pathologic response.

RESULTS

Twelve patients (15%) had a complete pathologic response (CPR), 23 patients (28%) had a near complete response (NCR), and 47 patients (57%) had significant residual disease present either at the primary site or in the axillary lymph nodes. The authors found that the nuclear grade and mitotic activity of pretreatment tumors were correlated significantly with CPR and NCR (P = 0.002 and P = 0.004). Mitosin also was correlated significantly with CPR and NCR (P = 0.028). A higher percentage of patients with Her2-neu-positive tumors had a CPR or an NCR (P = 0.152). CPR and NCR were not correlated significantly with disease stage (P = 0.186) or lymph node positivity (P = 0.498).

CONCLUSIONS

The current results indicate that tumor nuclear grade and tumor proliferative activity (mitotic activity and mitosin immunostaining) of pretreatment tumors in patients with breast carcinoma may serve as important indicators for the pathologic responsiveness of tumors to neoadjuvant, anthracycline-based chemotherapy.

Prediction of node-negative breast cancer outcome by histologic grading and S-phase analysis by flow cytometry: an Eastern Cooperative Oncology Group Study (2192)

Histologic evaluation and reporting of invasive breast cancer has effectively used Nottingham combined histologic grade (NCHG). This approach to predict outcome in invasive breast cancer has not been tested in multicenter cooperative trials. Histologic slides from selected breast cancer cases entered on node-negative Eastern Cooperative Oncology Group trials were assigned grades. Two pathologists evaluated cases for NCHG defined from differentiation, mitotic index, and nuclear grade. The study population consisted of separate samples from low- and high-risk strata, where low risk was estrogen receptor positive with a tumor size of less than 3 cm and high risk was estrogen receptor negative or tumor size greater than or equal to 3 cm. The rate of agreement was generally good, with 80% of cases classified the same for mitotic count and 76% of the cases classified the same for combined grade. There were no cases disagreeing from the lowest to the highest of the three categories. The median follow-up is 11.6 years, but for analysis of survival, this was truncated at 5 years. Mitotic index and combined grade as assessed by both pathologists showed significant associations with survival. High combined histologic grade was predictive for response to cyclophosphamide/methotrexate/5-fluorouracil (CMF) with survival differences at 5 years of 30% in the treated high-grade patients over the untreated patients. Overall, it is clear that pathologists can have close agreement in assignment of combined histologic grades, with highly significant prediction in univariate and borderline significance in multivariate analysis in prognostication of time to recurrence as well as survival. Thus, stratification used in these trials was highly prognostic as hoped, leaving a role for histologic grading in these relatively large tumors, more powerful than S-phase analysis in this series. In the subgroups of high-risk patients randomized between CMF and observation, there was a suggestion that the high-combined-grade group was predictive of treatment efficacy. We conclude that a combined histologic grade with defined criteria may be reliably assigned by practiced pathologists using readily available criteria, and that the measure may be of use in prognostication and prediction of therapeutic responsiveness when done in a technically ideal fashion.

Clinical course of breast cancer patients with complete pathologic primary tumor and axillary lymph node response to doxorubicin-based neoadjuvant chemotherapy

PURPOSE

To assess patient and tumor characteristics associated with a complete pathologic response (pCR) in both the breast and axillary lymph node specimens and the outcome of patients found to have a pCR after neoadjuvant chemotherapy for locally advanced breast cancer (LABC).

PATIENTS AND METHODS

Three hundred seventy-two LABC patients received treatment in two prospective neoadjuvant trials using four cycles of doxorubicin-containing chemotherapy. Patients had a total mastectomy with axillary dissection or segmental mastectomy and axillary dissection followed by four or more cycles of additional chemotherapy. Patients then received irradiation treatment of the chest-wall or breast and regional lymphatics. Median follow-up was 58 months (range, 8 to 99 months).

RESULTS

The initial nodal status, age, and stage distribution of patients with a pCR were not significantly different from those of patients with less than a pCR (P>.05). Patients with a pCR had initial tumors that were more likely to be estrogen receptor (ER)-negative (P<.01), and anaplastic (P = .01) but of smaller size (P<.01) than those of patients with less than a pCR. Upon multivariate analysis, the effects of ER status and nuclear grade were independent of initial tumor size. Sixteen percent of the patients in this study (n = 60) had a pathologic complete primary tumor response. Twelve percent of patients (n = 43) had no microscopic evidence of invasive cancer in their breast and axillary specimens. A pathologic complete primary tumor response was predictive of a complete axillary lymph node response (P<.01 ). The 5-year overall and disease-free survival rates were significantly higher in the group who had a pCR (89% and 87%, respectively) than in the group who had less than a pCR (64% and 58%, respectively; P<.01).

CONCLUSION

Neoadjuvant chemotherapy has the capacity to completely clear the breast and axillary lymph nodes of invasive tumor before surgery. Patients with LABC who have a pCR in the breast and axillary nodes have a significantly improved disease-free survival rate. However, a pCR does not entirely eliminate recurrence. Further efforts should focus on elucidating the molecular mechanisms associated with this response.