Pathobiology of preoperative chemotherapy: findings from the National Surgical Adjuvant Breast and Bowel (NSABP) protocol B-18

Histologic changes associated with false-negative sentinel lymph nodes after preoperative chemotherapy in patients with confirmed lymph node-positive breast cancer before treatment

BACKGROUND

A wide range of false-negative rates has been reported for sentinel lymph node (SLN) biopsy after preoperative chemotherapy. The purpose of this study was to determine whether histologic findings in negative SLNs after preoperative chemotherapy are helpful in assessing the accuracy of SLN biopsy in patients with confirmed lymph node-positive disease before treatment.

METHODS

Eighty-six patients with confirmed lymph node-positive disease at presentation underwent successful SLN biopsy and axillary dissection after preoperative chemotherapy at a single institution between 1994 and 2007. Available hematoxylin and eosin-stained sections from patients with negative SLNs were reviewed, and associations between histologic findings in the negative SLNs and SLN status (true negative vs false negative) were evaluated.

RESULTS

Forty-seven (55%) patients had at least 1 positive SLN, and 39 (45%) patients had negative SLNs. The false-negative rate was 22%, and the negative predictive value was 67%. The negative SLNs from 17 of 34 patients with available slides had focal areas of fibrosis, some with associated foamy parenchymal histiocytes, fat necrosis, or calcification. These histologic findings occurred in 15 (65%) of 23 patients with true-negative SLNs and in only 2 (18%) of 11 patients with false-negative SLNs (P = .03, Fisher exact test, 2-tailed). The lack of these histologic changes had a sensitivity and specificity for identifying a false-negative SLN of 82% and 65%, respectively.

CONCLUSIONS

Absence of treatment effect in SLNs after chemotherapy in patients with lymph node-positive disease at initial presentation has good sensitivity but low specificity for identifying a false-negative SLN.

Trastuzumab-based neoadjuvant therapy in patients with HER2-positive breast cancer

Overexpression, or gene amplification, of the human epidermal growth factor receptor 2 (HER2) is evident in 20% to 25% of breast cancers. The biologic agent trastuzumab is an HER2-targeted monoclonal antibody that inhibits the proliferation of tumor cells and induces tumor cell death through multiple mechanisms of action. Currently, trastuzumab is approved for use in the adjuvant and metastatic settings. Trials combining trastuzumab with neoadjuvant chemotherapy suggest that patients with HER2-positive breast cancer also may benefit from preoperative trastuzumab. For this article, the author reviewed efficacy and safety data from key studies of patients who received neoadjuvant trastuzumab-based therapy. Studies were identified from literature searches of publication and congress databases. The results of 3 large phase 3 trials (the M. D. Anderson Cancer Center neoadjuvant trastuzumab trial, the Neoadjuvant Herceptin [NOAH] trial, and the German Breast Group/Gynecologic Oncology Study Group "GeparQuattro" trial) demonstrated that, compared with chemotherapy alone, neoadjuvant trastuzumab plus chemotherapy significantly increased pathologic complete response rates to as high as 65%. Improvements in disease-free, overall, and event-free survival also were reported in the NOAH trial. In addition to demonstrated efficacy, a low incidence of cardiac dysfunction suggests that neoadjuvant trastuzumab is both effective and well tolerated. Similar results have been reported in a range of phase 2 studies using different trastuzumab-based regimens. These encouraging data led the National Comprehensive Cancer Network to recommend treating patients who have operable, locally advanced, HER2-positive breast cancer with neoadjuvant paclitaxel plus trastuzumab followed by 5-fluorouracil, epirubicin, and cyclophosphamide plus trastuzumab.

Molecular basis for therapy resistance

Chemoresistance remains the main reason for therapeutic failure in breast cancer as well as most other solid tumours. While gene expression profiles related to prognosis have been developed, so far use of such signatures as well as single markers has been of limited value predicting drug resistance. Novel technologies, in particular with regard to high through-put sequencing holds great promises for future identification of the key "driver" mechanisms guiding chemosensitivity versus resistance in breast cancer as well as other malignant conditions.

Breast cancer prognosis and occult lymph node metastases, isolated tumor cells, and micrometastases

BACKGROUND

The prognostic relevance of isolated tumor cells and micrometastases in lymph nodes from patients with breast cancer has become a major issue since the introduction of the sentinel lymph node procedure. We conducted a systematic review of this issue.

METHODS

Studies published from January 1, 1977, until August 11, 2008, were identified by use of MEDLINE, EMBASE, and the Cochrane Library. A total of 58 studies (total number of patients = 297,533) were included and divided into three categories according to the method for pathological assessment of the lymph nodes: cohort studies with single-section pathological examination of axillary lymph nodes (n = 285,638 patients), occult metastases studies with retrospective examination of negative lymph nodes by step sectioning and/or immunohistochemistry (n = 7740 patients), and sentinel lymph node biopsy studies with intensified work-up of the sentinel but not of the nonsentinel lymph nodes (n = 4155 patients). We used random-effects meta-analyses to calculate pooled estimates of the relative risks (RRs) of 5- and 10-year disease recurrence and death and the multivariably corrected pooled hazard ratio (HR) of overall survival of the cohort studies.

RESULTS

In the cohort studies, the presence (vs the absence) of metastases of 2 mm or less in diameter in axillary lymph nodes was associated with poorer overall survival (pooled HR of death = 1.44, 95% confidence interval [CI] = 1.29 to 1.62). In the occult metastases studies, the presence (vs the absence) of occult metastases was associated with poorer 5-year disease-free survival (pooled RR = 1.55, 95% CI = 1.32 to 1.82) and overall survival (pooled RR = 1.45, 95% CI = 1.11 to 1.88), although these endpoints were not consistently assessed in multivariable analyses. Sentinel lymph node biopsy studies were limited by small patient groups and short follow-up.

CONCLUSION

The presence (vs the absence) of metastases of 2 mm or less in diameter in axillary lymph nodes detected on single-section examination was associated with poorer disease-free and overall survival.

Common and discriminative clinicopathological features between breast cancers with pathological complete response or progressive disease in response to neoadjuvant chemotherapy

PURPOSE

To clarify clinicopathological similarities and differences between breast carcinomas that achieve pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) and those showing progressive disease (PD) during NAC, we compared pre-NAC clinicopathological characteristics between these tumors.

METHODS

Subjects comprised 32 patients (6%) achieved pCR and 33 patients (7%) showed PD of 494 patients (498 breasts) with stage II or III breast carcinoma who underwent anthracycline-based or taxane chemotherapy or both, followed by surgery, between 2000 and 2006. We compared patient characteristics before NAC, and histomorphology, immunohistochemistry, and molecular subtypes of tumors using pre-NAC biopsy samples. Immunohistochemistry included estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor-2 (HER2), epidermal growth factor receptor (EGFR), cytokeratin 5/6 (CK5/6). Molecular subtypes were defined by ER, PgR, HER2, EGFR, and CK5/6. We compared these factors between pCR and PD using univariate chi (2) testing and multivariate logistic regression analyses.

RESULTS

No significant differences between groups were seen regarding NAC regimens. Solid-tubular carcinoma (53% of pCR, 61% of PD), histological grade 3 (78% of pCR, 79% of PD), ER-status (91% of pCR, 82% of PD), and basal-like subtype (44% of pCR, 58% of PD) were often observed in both groups. In multivariate analyses, lower clinical N stage at diagnosis (P = 0.004) and HER2/ER-PgR- subtype (P = 0.020) were significantly associated with pCR.

CONCLUSIONS

Breast carcinomas achieving pCR or showing PD with NAC have common peculiar characteristics such as solid-tubular carcinoma, high grade, hormone receptor negativity, and basal-like subtype. Conversely, discriminative factors include clinical N stage at diagnosis and HER2/ER-PgR- subtype.

Neoadjuvant chemotherapy for locally advanced breast cancer

Preoperative systemic therapy is the standard of care in locally advanced breast cancer. In this setting, the intent of preoperative systemic therapy is to expand surgical options and to improve survival. Locally advanced and inflammatory breast cancer have different biological features, but they share the use of preoperative (primary, neoadjuvant) systemic therapy as the initial treatment of choice. The management of these patients necessitates involvement of a multidisciplinary team from the onset and during therapy. The eradication of invasive cancer from the breast and axillary lymph nodes, pathologic complete response, is a predictor of outcome associated with improved disease-free and overall survival. However, conventional chemotherapy regimens result in pathologic complete response in only a minority of patients. The management of patients with residual invasive disease after preoperative therapy is a common clinical problem for which additional research is necessary. The differential expression of genes and pathways in locally advanced and inflammatory breast cancer allows for the exploitation of targeted therapy, and early trials have shown exciting target and tumor effects. Much work remains, and future trials combining targeted and conventional therapies based on molecular subtypes and/or specific targets are needed if we hope to improve survival for patients with locally advanced breast cancer.

Assessment of residual tumour by FDG-PET: conventional imaging and clinical examination following primary chemotherapy of large and locally advanced breast cancer

Background:

The aim of this was to evaluate FDG-PET (2-(fluorine-18)-fluoro-2-deoxy-D-glucose positron emission tomography) for assessment of residual tumour after primary chemotherapy of large and locally advanced breast cancer in comparison with conventional imaging modalities.

Methods:

In a prospective multicentre trial, 99 patients underwent one or more breast imaging modalities before surgery in addition to clinical examination, namely, FDG-PET (n=89), mammography (n=47), ultrasound (n=46), and magnetic resonance imaging (MRI) (n=46). The presence of residual tumour by conventional imaging, dichotomised as positive or negative, and the level of FDG uptake (standardised uptake values, SUV) were compared with histopathology, which served as the reference standard. Patients with no residual tumour or only small microscopic foci of residual tumour were classified as having minimal residual disease and those with extensive microscopic and macroscopic residual tumour tissue were classified as having gross residual disease.

Results:

By applying a threshold SUV of 2.0, the sensitivity of FDG-PET for residual tumour was 32.9% (specificity, 87.5%) and increased to 57.5% (specificity, 62.5%) at a threshold SUV of 1.5. Conventional imaging modalities were more sensitive in identifying residual tumour, but had a low corresponding specificity; sensitivity and specificity were as follows: MRI 97.6 and 40.0%, mammography 92.5 and 57.1%, ultrasound 92.0 and 37.5%, respectively. Breast MRI provided the highest accuracy (91.3%), whereas FDG-PET had the lowest accuracy (42.7%).

Conclusions:

FDG-PET does not provide an accurate assessment of residual tumour after primary chemotherapy of breast cancer. Magnetic resonance imaging offers the highest sensitivity, but all imaging modalities have distinct limitations in the assessment of residual tumour tissue when compared with histopathology.

PET and PET-CT Imaging in Treatment Monitoring of Breast Cancer

Breast cancer is one of the more responsive solid tumors with a wide range of systemic therapy options. The treatment of newly diagnosed breast cancer is primarily determined by the extent of disease and generally includes surgery, radiation, and chemotherapy. This article discusses the PET and PET-CT modalities for evaluating treatment response in breast cancer.

Tumor dormancy and metastasis

Metastasis--the spread of cancer to distant organs--is responsible for most cancer deaths. Current adjuvant therapy is based on prognostic indicators that stratify patients into defined risk groups. However, some patients believed to have a good prognosis nonetheless develop metastases, in some cases many years after apparently successful treatment of their primary cancer. This period of clinical dormancy leads to many questions about how best to manage patients, including how to better assign risk of late recurrence, how long to monitor patients, and whether some patients will benefit from extended therapy to prevent late recurrences. The development of targeted therapies with fewer side effects is leading to clinical trials aimed at determining the effectiveness of such long-term therapy. However, much remains to be learned about tumor dormancy. Experimental studies are shedding light on biological and molecular mechanisms potentially responsible for tumor dormancy. Emerging research into tumor initiating cells, immunotherapy, and metastasis suppressor genes, may lead to new approaches for targeted antimetastatic therapy to prolong tumor dormancy. An improved understanding of tumor dormancy is needed for better management of patients at risk for late-developing metastases.

Cancer stem cells: a guide for skeptics

Cancer stem cells (CSC) were postulated to exist many years ago as cells within a tumor that regenerate the tumor following treatment. A stochastic clonal evolution model was used to explain observed tumor heterogeneity. Recently, xenotransplantation studies have demonstrated that prospectively identifiable subpopulations from human cancers can initiate tumors in immune deficient mice, and these results along with recent advances in stem cell biology have generated much excitement in the cancer field. The modern CSC theory posits a hierarchy of cells analogous to normal stem cell development. Some controversy remains, however, as to whether these tumor initiating cells truly represent CSC, and whether the modern CSC field can live up to the promise of providing improved cancer treatments based on a novel model of cancer biology. Recent data from CSC investigators are discussed critically.

Pathology of breast carcinomas after neoadjuvant chemotherapy: an overview with recommendations on specimen processing and reporting

CONTEXT

Currently, more women are being treated with chemotherapy or hormonal agents before surgery (neoadjuvant chemoendocrine therapy) for earlier-stage operable breast carcinoma. The pathologic examination of these specimens can be quite challenging.

OBJECTIVE

To give an overview of (1) pathologic changes that occur during treatment, (2) systems for evaluating response to treatment, and (3) recommendations for pathologic examination and reporting of such cases.

DATA SOURCES

The recommendations are based on the review of selected literature on breast carcinoma after neoadjuvant therapy and the authors' personal experience with the clinical and pathologic characteristics of cases from each of the authors' own institutions.

CONCLUSIONS

Pathologists play a key role in the evaluation of pathologic response, which is extremely important as a prognostic factor for individual patients, as a short-term endpoint for clinical trials, and as an adjunct for research studies. Therefore, surgical pathologists must be familiar with the gross examination, sampling, and reporting of breast carcinomas after neoadjuvant therapy.

Multidisciplinary care for patients with breast cancer

The care of patients with breast cancer has become increasingly complex with advancements in diagnostic modalities, surgical approaches, and adjuvant treatments. A multidisciplinary approach to breast cancer care is essential to the successful integration of available therapies. This article addresses the key components of multidisciplinary breast cancer care, with a special emphasis on new and emerging approaches over the past 10 years in the fields of diagnostics, surgery, radiation, medical oncology, and plastic surgery.

Response to therapy in breast cancer

Increasing numbers of patients with newly diagnosed breast cancer receive primary systemic therapy followed by surgery. Histopathology provides an accurate assessment of treatment efficacy on the basis of the extent of residual tumor and regressive changes within tumor tissue. However, only approximately 20% of breast cancer patients achieve a pathologic complete response, a fact that necessitates methods for monitoring therapeutic effectiveness early during therapy. (18)F-FDG PET and (18)F-FDG PET/CT provide essential information regarding a response to primary chemotherapy. Patients with low tumor metabolic activity on pretreatment (18)F-FDG PET are not likely to achieve a histopathologic response. The degree of changes in (18)F-FDG uptake after the initiation of therapy is correlated with the histopathologic response after the completion of therapy. Thus, tumor metabolic changes assessed early during therapy predict therapeutic effectiveness in individual patients. Early identification of ineffective therapy also might be helpful in patients with metastatic breast cancer because many palliative treatment options are available. Changes in metabolic activity generally occur earlier than changes in tumor size, which is the current standard for the assessment of a response. Although treatment stratification based on a metabolic response is an exciting potential application of PET, specific PET response assessment criteria still need to be developed and validated on the basis of patient outcomes before changes in treatment regimens can be implemented. There is increasing clinical evidence for metastatic breast cancer and other tumors that (18)F-FDG PET/CT is the most accurate imaging procedure for assessment of the response at the end of treatment when both CT information and tumor metabolic activity are considered. Importantly, in the setting of primary chemotherapy, neither PET/CT nor conventional imaging procedures can assess the extent of residual breast cancer as accurately as histopathology. Observation of changes in tumor blood flow or tumor cell proliferation is an additional encouraging approach for predicting a response. Ultimately, the prediction of therapeutic effectiveness by PET and PET/CT could help to individualize treatment and to avoid ineffective chemotherapies, with their associated toxicities.

Genomic grade index is associated with response to chemotherapy in patients with breast cancer

PURPOSE The genomic grade index (GGI) is a 97-gene measure of histological tumor grade. High GGI is associated with decreased relapse-free survival in patients receiving either endocrine or no systemic adjuvant therapy. Herein we examined whether GGI predicts pathologic response to neoadjuvant chemotherapy in patients with HER-2-normal breast cancer. METHODS Gene expression data (gene chips) was generated from fine-needle aspiration biopsies (n = 229) prospectively collected before neoadjuvant paclitaxel, fluorouracil, doxorubicin, and cyclophosphamide chemotherapy. Pathologic response was quantified using the residual cancer burden (RCB) method. The association between the GGI and pathologic response was assessed in univariate and multivariate analyses. The performance of a response predictor combining clinical variables and GGI was evaluated under cross-validation. Results Eighty-five percent of grade 1 tumors had low GGI, 89% of grade 3 tumors had high GGI, and 63% of grade 2 tumors had low GGI. Among both estrogen receptor (ER)-positive and -negative cancers, high GGI score was associated with pathologic complete response (RCB-0) or minimal residual disease (RCB-1). A multivariate model combining GGI and clinical parameters had an overall accuracy of 71%, compared with 58% for the GGI alone, for prediction of pathologic response. However, high GGI score was also associated with significantly worse distant relapse-free survival in patients with ER-positive cancer (P = .005), and was not associated with survival in patients with ER-negative cancer. CONCLUSION High GGI is associated with increased sensitivity to neoadjuvant paclitaxel plus fluorouracil, adriamycin, and cyclophosphamide chemotherapy in both ER-negative and ER-positive patients, but it remains a predictor of worse survival in ER-positive patients.

Incidence of pathologic complete response in women treated with preoperative chemotherapy for locally advanced breast cancer: correlation of histology, hormone receptor status, Her2/Neu, and gross pathologic findings

Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer and is used increasingly for large operable breast cancer. The aim of this study was to assess the rate of pathologic complete response (pCR) in our patient population with locally advanced breast cancer and identify predictive factors for pCR after neoadjuvant chemotherapy. We studied a cohort of 205 patients and compared histologic features and biomarkers in the pretreatment biopsy with the corresponding pathologic response in the subsequent resection specimen. A pCR was defined as the absence of any microscopic evidence of tumor in the mastectomy specimen and axillary lymph node dissection. The tumor size was reduced in 60% of patients; 16 patients had a pCR. Histologic grade, histologic type, and hormone status did correlate with a pathologic response. None of the 29 invasive pure micropapillary carcinomas had a pCR. Pathologic complete response among Mexican patients with locally advanced breast cancer is low (8%), and the presence of invasive pure micropapillary carcinoma could be an independent predictor for pCR.

Pure and predominantly pure intralymphatic breast carcinoma after neoadjuvant chemotherapy: an unusual and adverse pattern of residual disease

Neoadjuvant chemotherapy is standard of care for patients with locally advanced breast cancer. Patients who achieve a pathologic complete response have a more favorable outcome than those who do not; however, a standard system for classifying residual disease has not been adopted. Various definitions of complete response exist, some of which allow for minimal residual invasive or in situ carcinoma. The pattern of residual carcinoma restricted to lymphatic spaces without stromal invasion, herein called pure intralymphatic carcinoma, has not been well addressed. Neither has the pattern of minimal residual stromal invasive cancer accompanied by an extensive intralymphatic component, herein called predominantly pure intralymphatic carcinoma. We report the incidence, clinicopathologic features, and clinical significance of pure and predominantly pure intralymphatic carcinoma in a cohort of 146 neoadjuvant-treated breast cancer patients. We also evaluate the use of the immunohistochemical lymphatic marker D2-40 in these tissues exposed to neoadjuvant chemotherapy. Six patients (4%) had residual pure intralymphatic carcinoma. No gross abnormalities were present in the mastectomy specimens except for 1 case that had a discrete mass, corresponding to residual in situ carcinoma. Residual intralymphatic tumor size ranged from 0.2 to 6 cm. All but one had residual positive lymph nodes. Residual predominantly pure intralymphatic carcinoma was found in 5/146 (4%) patients. A discrete gross mass was observed in 3/5 specimens. Whereas residual stromal invasive carcinoma ranged in size from 0.1 to 1.8 cm, the intralymphatic component ranged from 6 to 9.3 cm. All had residual positive lymph nodes. D2-40 adequately marked lymphatic endothelium in all cases tested. Death occurred in 6/11 (55%) versus 17/135 (13%) patients with or without pure/predominantly pure intralymphatic carcinoma, respectively. After controlling for tumor stage, the presence of either of these residual intralymphatic patterns was associated with a 3-fold increase in death (Cox proportional hazards ratio=3.59, 95% confidence interval, 1.29, 9.99, P=0.014). Elevated risk for disease progression was also observed but this was not statistically significant. We conclude that pure/predominantly pure intralymphatic carcinoma is a clinically significant pattern of residual disease. This may be an underrecognized pattern because of the discordance between gross and microscopic findings and because of challenges in diagnosing intralymphatic carcinoma. D2-40 immunostaining is useful in this setting. Current staging criteria should be clarified to define whether extensive intralymphatic tumor should be incorporated in tumor stage assignment.

Monitoring Primary Systemic Therapy of Large and Locally Advanced Breast Cancer by Using Sequential Positron Emission Tomography Imaging With [18F]Fluorodeoxyglucose

Purpose

To evaluate positron emission tomography (PET) using [18F]fluorodeoxyglucose (FDG) for prediction of histopathologic response early during primary systemic therapy of large or locally advanced breast cancer.

Patients and Methods

In a prospective multicenter trial, 272 FDG-PET scans were performed in 104 patients at baseline (n = 104) and after the first (n = 87) and second cycle (n = 81) of chemotherapy. The level and relative changes in standardized uptake value (SUV) of FDG uptake were assessed regarding their ability to predict histopathologic response. All patients underwent surgery after chemotherapy, and histopathologic response defined as minimal residual disease or gross residual disease served as the reference standard.

Results

Seventeen (16%) of 104 patients were histopathologic responders and 87 were (84%) nonresponders. All patients for whom baseline SUV was less than 3.0 (n = 24) did not achieve a histopathologic response. SUV decreased by 51% ± 18% after the first cycle of chemotherapy in histopathologic responders (n = 15), compared with 37% ± 21% in nonresponders (n = 54; P = .01). A threshold of 45% decrease in SUV correctly identified 11 of 15 responders, and histopathologic nonresponders were identified with a negative predictive value of 90%. Similar results were found after the second cycle when using a threshold of 55% relative decrease in SUV.

Conclusion

FDG-PET allows for prediction of treatment response by the level of FDG uptake in terms of SUV at baseline and after each cycle of chemotherapy. Moreover, relative changes in SUV after the first and second cycle are a strong predictor of response. Thus, FDG-PET may be helpful for individual treatment stratification in breast cancer patients.

Fifteen-year median follow-up results after neoadjuvant doxorubicin, followed by mastectomy, followed by adjuvant cyclophosphamide, methotrexate, and fluorouracil (CMF) followed by radiation for stage III breast cancer: a phase II trial (CALGB 8944)

PURPOSE

To describe long-term results of a multimodality strategy for stage III breast cancer utilizing neoadjuvant doxorubicin followed by mastectomy, CMF, and radiotherapy.

PATIENTS AND METHODS

Women with biopsy-proven, clinical stage III breast cancer and adequate organ function were eligible. Neoadjuvant doxorubicin (30 mg/m(2) days 1-3, every 28 days for 4 cycles) was followed by mastectomy, in stable or responding patients. Sixteen weeks of postoperative CMF followed (continuous oral cyclophosphamide (2 mg/kg/day); methotrexate (0.7 mg/kg IV) and fluorouracil (12 mg/kg IV) weekly, weeks 1-8, and than biweekly, weeks 9-16). Radiation therapy followed adjuvant chemotherapy.

RESULTS

Clinical response rate was 71% (79/111, 95% CI = 62-79%), with 19% complete clinical response. Pathologic complete response was 5% (95% CI = 2-11%). Median follow-up is 15.6 years. Half of the patients progressed by 2.2 years; half died by 5.4 years (range 6 months-15 years). The hazard of dying was greatest in the first 5 years after diagnosis and declined thereafter. Time to progression and overall survival were predicted by number of pathologically involved lymph nodes (TTP: HR [10 vs. 1 node] 2.40, 95% CI = 1.63-3.53, P < 0.0001; OS: HR 2.50, 95% CI = 1.74-3.58, P < 0.0001).

CONCLUSIONS

After multimodality treatment for locally advanced breast cancer, long-term survival was correlated with the number of pathologically positive lymph nodes, but not to clinical response. The hazard of death was highest during the first 5 years after diagnosis and declined thereafter, indicating a possible intermediate endpoint for future trials of neoadjuvant treatment.

A stroma-related gene signature predicts resistance to neoadjuvant chemotherapy in breast cancer

To better understand the relationship between tumor-host interactions and the efficacy of chemotherapy, we have developed an analytical approach to quantify several biological processes observed in gene expression data sets. We tested the approach on tumor biopsies from individuals with estrogen receptor-negative breast cancer treated with chemotherapy. We report that increased stromal gene expression predicts resistance to preoperative chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide (FEC) in subjects in the EORTC 10994/BIG 00-01 trial. The predictive value of the stromal signature was successfully validated in two independent cohorts of subjects who received chemotherapy but not in an untreated control group, indicating that the signature is predictive rather than prognostic. The genes in the signature are expressed in reactive stroma, according to reanalysis of data from microdissected breast tumor samples. These findings identify a previously undescribed resistance mechanism to FEC treatment and suggest that antistromal agents may offer new ways to overcome resistance to chemotherapy.

Diffuse optical spectroscopy measurements of healing in breast tissue after core biopsy: case study

Diffuse optical spectroscopy (DOS) has been used to monitor and predict the effects of neoadjuvant (i.e., presurgical) chemotherapy in breast cancer patients in several pilot studies. Because patients with suspected breast cancers undergo biopsy prior to treatment, it is important to understand how biopsy trauma influences DOS measurements in the breast. The goal of this study was to measure the effects of a standard core breast biopsy on DOS measurements of tissue deoxyhemoglobin, hemoglobin, water, and bulk lipid concentrations. We serially monitored postbiopsy effects in the breast tissue in a single subject (31-year-old premenopausal female) with a 37x18x20 mm fibroadenoma. A baseline measurement and eight weekly postbiopsy measurements were taken with a handheld DOS imaging instrument. Our instrument used frequency domain photon migration combined with broadband steady-state spectroscopy to characterize tissues via quantitative measurements of tissue absorption and reduced scattering coefficients from 650 to 1000 nm. The concentrations of significant near-infrared (NIR) absorbers were mapped within a 50 cm(2) area over the biopsied region. A 2-D image of a contrast function called the tissue optical index (TOI=deoxyhemoglobinxwaterbulk lipid) was generated and revealed that a minimum of 14 days postbiopsy was required to return TOI levels in the biopsied area to their prebiopsy levels. Changes in the TOI images of the fibroadenoma also reflected the progression of the patient's menstrual cycle. DOS could therefore be useful in evaluating both wound-healing response and the effects of hormone and hormonal therapies in vivo.

Highly variable response to cytotoxic chemotherapy in carcinoma-associated fibroblasts (CAFs) from lung and breast

Background

Carcinoma-associated fibroblasts (CAFs) can promote carcinogenesis and tumor progression. Only limited data on the response of CAFs to chemotherapy and their potential impact on therapy outcome are available. This study was undertaken to analyze the influence of chemotherapy on carcinoma-associated fibroblasts (CAFs) in vitro and in vivo.

Methods

The in vivo response of stromal cells to chemotherapy was investigated in 22 neoadjuvant treated breast tumors on tissue sections before and after chemotherapy. Response to chemotherapy was analyzed in vitro in primary cultures of isolated CAFs from 28 human lung and 9 breast cancer tissues. The response was correlated to Mdm2, ERCC1 and TP53 polymorphisms and TP53 mutation status. Additionally, the cytotoxic effects were evaluated in an ex vivo experiment using cultured tissue slices from 16 lung and 17 breast cancer specimens.

Results

Nine of 22 tumors showed a therapy-dependent reduction of stromal activity. Pathological response of tumor or stroma cells did not correlate with clinical response. Isolated CAFs showed little sensitivity to paclitaxel. In contrast, sensitivity of CAFs to cisplatinum was highly variable with a GI50 ranging from 2.8 to 29.0 μM which is comparable to the range observed in tumor cell lines. No somatic TP53 mutation was detected in any of the 28 CAFs from lung cancer tissue. In addition, response to cisplatinum was not significantly associated with the genotype of TP53 nor Mdm2 and ERCC1 polymorphisms. However, we observed a non-significant trend towards decreased sensitivity in the presence of TP53 variant genotype. In contrast to the results obtained in isolated cell culture, in tissue slice culture breast cancer CAFs responded to paclitaxel within their microenvironment in the majority of cases (9/14). The opposite was observed in lung cancer tissues: only few CAFs were sensitive to cisplatinum within their microenvironment (2/15) whereas a higher proportion responded to cisplatinum in isolated culture.

Conclusion

Similar to cancer cells, CAF response to chemotherapy is highly variable. Beside significant individual/intrinsic differences the sensitivity of CAFs seems to depend also on the cancer type as well as the microenvironment.

Dynamic contrast-enhanced MRI for prediction of breast cancer response to neoadjuvant chemotherapy: initial results

OBJECTIVE

The aim of this study was to establish changes in contrast-enhanced MRI of breast cancer during neoadjuvant chemotherapy that are indicative of pathology outcome.

MATERIALS AND METHODS

In 54 patients with breast cancer, dynamic contrast-enhanced MRI was performed before chemotherapy and after two chemotherapy cycles. Imaging was correlated with final histopathology. Multivariate analysis with cross-validation was performed on MRI features describing kinetics and morphology of contrast uptake in the early and late phases of enhancement. Receiver operating characteristic (ROC) analysis was used to develop a guideline that switches patients at high risk for incomplete remission to a different chemotherapy regimen while maintaining first-line therapy in 95% of patients who are not at risk (i.e., high specificity).

RESULTS

Change in largest diameter of late enhancement during chemotherapy was the single most predictive MRI characteristic for tumor response in multivariate analysis (A(z) [area under the ROC curve] = 0.73, p < 0.00001). Insufficient (< 25%) decrease in largest diameter of late enhancement during chemotherapy was most indicative of residual tumor at final pathology. Using this criterion, the fraction of unfavorable responders indicated by MRI was 41% (22/54). Approximately half (44%, 14/32) of the patients who showed favorable response at MRI achieved complete remission at pathology. Conversely, 95% (21/22) of patients who showed unfavorable response at MRI had residual tumor at pathology.

CONCLUSION

Reduction of less than 25% in largest diameter of late enhancement during neoadjuvant chemotherapy shows the potential to predict residual tumor after therapy with high specificity.

Staging of breast cancer in the neoadjuvant setting

The use of neoadjuvant chemotherapy has become more prevalent in the treatment of breast cancer patients. The finding of a pathologic complete response to neoadjuvant chemotherapy (no evidence of residual invasive cancer in the breast and lymph nodes at the time of surgical resection) has been shown to correlate with improved survival. The current version of the American Joint Committee on Cancer (AJCC) staging for breast cancer has a pretreatment clinical stage designation that is determined by clinical and radiographic examination of the patient and a postoperative pathologic stage classification based on the findings in the breast and regional lymph nodes removed at surgery. Pathologic staging has not been validated for patients receiving neoadjuvant chemotherapy; thus, prognosis is determined for these patients based on the pretreatment clinical stage. We hypothesized that clinical and pathologic staging variables could be combined with biological tumor markers to provide a novel means of determining prognosis for patients treated with neoadjuvant chemotherapy. Two scoring systems, based on summing binary indicators for clinical and pathologic substages, negative estrogen receptor status, and grade 3 tumor pathology, were devised to predict 5-year patient outcomes. These scoring systems facilitated separation of the study population into more refined subgroups by outcome than the current AJCC staging system for breast cancer, and provide a novel means for evaluating prognosis after neoadjuvant therapy.

Neoadjuvant chemotherapy in invasive breast cancer results in a lower axillary lymph node count

BACKGROUND

It is essential to have the highest level of confidence in axillary staging assessment. Many surgeons and pathologists believe that fewer lymph nodes are present in axillary dissection specimens of women treated by neoadjuvant chemotherapy. Consequently, the purpose of this study was to compare the lymph node counts of axillary dissection specimens from patients having received neoadjuvant chemotherapy with those of patients treated with primary operation.

STUDY DESIGN

A retrospective analysis of a prospective database from our institution identified 283 women with invasive breast cancer who underwent level I and II axillary lymph node dissections. Women from the neoadjuvant chemotherapy group (n=107) were compared with those from the primary surgery group (n=176). The total number of lymph nodes harvested was considered as a continuous variable, but also dichotomized into two categories (< 10 and >or=10). Its correlation with the different variables was analyzed.

RESULTS

The median number of lymph nodes retrieved in the neoadjuvant chemotherapy group was 10.0 (range 0 to 38) compared with 12.5 (range 0 to 30) in the control group (p=0.002). There were also significantly more patients with fewer than 10 lymph nodes recovered in the neoadjuvant group (45 versus 28%, p=0.007). Logistic regression showed that neoadjuvant chemotherapy was the only factor associated with retrieval of fewer than 10 lymph nodes.

CONCLUSIONS

This study suggests that administration of neoadjuvant chemotherapy to breast cancer patients results in a reduced number of lymph nodes retrieved in the axillary dissection specimens.

Residual specimen cellularity after neoadjuvant chemotherapy for breast cancer

BACKGROUND

Neoadjuvant chemotherapy for breast cancer reduces tumour cellularity, the percentage of the primary tumour area that is composed of invasive tumour cells. Minimal residual tumour cellularity (5 per cent or less of tumour area composed of invasive tumour cells) may be associated with an increased risk of false-negative intraoperative margins. The aim of this study was to evaluate the incidence of minimal residual tumour cellularity after neoadjuvant chemotherapy and its impact on the frequency of false-negative margins and conversion from breast-conserving surgery to mastectomy.

METHODS

The final pathology slides of 510 patients who had surgery after neoadjuvant chemotherapy were reviewed.

RESULTS

Of 396 patients with residual invasive breast cancer after neoadjuvant chemotherapy, 100 specimens (25.3 per cent) had minimal residual cellularity; this was more frequent in patients with invasive lobular carcinoma (17.0 versus 5.1 per cent; P < 0.001) or well and moderately differentiated carcinoma (68.0 versus 52.4 per cent; P = 0.007). Among 149 patients who had initial breast-conserving surgery, false-negative intraoperative margin rates were 23 per cent in specimens with minimal and 13.8 per cent in those with higher residual cellularity (P = 0.210). There was no significant difference in the rate of conversion to mastectomy between the groups.

CONCLUSION

Minimal residual cellularity after neoadjuvant chemotherapy occurred in about 25 per cent of specimens, but did not alter the rate of false-negative intraoperative margins.

Histological features of breast cancer, highly sensitive to chemotherapy

BACKGROUND

To establish tailor-made therapy for breast cancer, we investigated the possibility of predicting chemotherapy sensitive cases based on pre-therapeutic histological features.

METHODS

A total of 87 breast cancer patients underwent neoadjuvant chemotherapy with a paclitaxel (80 mg/m(2)/q1w, 12 courses)or an epirubicin regimen (90 mg/m(2)/q3wks, 4 courses). We investigated the chemo-sensitivity of invasive ductal carcinoma, solid-tubular carcinoma consisting of highly malignant cancer cells with many mitoses. We refer to this type of carcinoma as " chemo-sensitive carcinoma " and compared the histological therapeutic effects of chemo-sensitive and chemo-insensitive carcinomas.

RESULTS

1) Out of 87 patients, 20 cases (23%) showed the histological features of chemo-sensitive carcinomas on pre-therapeutic needle biopsy specimens. The remaining 67 cases (77%) were classified as chemo-insensitive carcinoma. 2) Histologically marked or complete response were observed in 50% (10/20) of chemo-sensitive carcinomas and 10% (7/67) of chemo-insensitive carcinomas (chi(2)=15.33, p=0.0001). Multivariate analysis of chemo-sensitive carcinoma, including HER2, hormone receptor and p53 status, revealed that chemo-sensitive carcinoma had a significant correlation with the histological therapeutic effects (p=0.01119). 3) Pathological complete response (pCR) was achieved in 35% (7/20) of chemo-sensitive carcinomas and 1.5% (1/67)of chemo-insensitive carcinomas (chi(2)=20.71, p<0.0001). Multivariate analysis revealed that chemo-sensitive carcinoma had a significant correlation with pCR (p=0.0091).

CONCLUSION

The histological features of chemo-sensitive carcinoma were significant predictive factors for chemotherapeutic efficacy.

Combined Use of Clinical and Pathologic Staging Variables to Define Outcomes for Breast Cancer Patients Treated With Neoadjuvant Therapy

Purpose

Neoadjuvant chemotherapy is being used with increasing frequency for operable breast cancer. We hypothesized that by using clinical and pathologic staging parameters, in conjunction with biologic tumor markers, a novel means of determining prognosis for patients treated with neoadjuvant chemotherapy could be facilitated.

Patients and Methods

A prospective database of patients treated with neoadjuvant chemotherapy from 1997 to 2003 was reviewed, and 932 patients meeting inclusion criteria were identified. Clinical and pathologic tumor characteristics, treatment regimens, and patient outcomes were recorded. Cox proportional hazards models were used to create two prognostic scoring systems. American Joint Committee on Cancer (AJCC) clinical and pathologic staging parameters and biologic tumor markers were investigated to devise the scoring systems.

Results

Median follow-up time was 5 years (range, 0.4 to 9.4 years). Five-year disease-specific survival rate was 96% for patients who experienced a pathologic complete response (pCR; n = 130) compared with 87% for patients who did not have a pCR (n = 802; P = .001). Two scoring systems, based on summing binary indicators for clinical substages ≥ IIB and ≥ IIIB, pathologic substages ≥ ypIIA and ≥ ypIIIC, negative estrogen receptor status, and grade 3 pathology, were devised to predict 5-year patient outcomes. These scoring systems facilitated separation of the study population into more refined subgroups by outcome than the current AJCC staging system.

Conclusion

The scoring systems derived in this work provide a novel means for evaluating prognosis after neoadjuvant therapy. Future work will focus on prospective validation of these scoring systems and refinement of the scoring systems through addition of new biologic markers.

Validation of gene signatures that predict the response of breast cancer to neoadjuvant chemotherapy: a substudy of the EORTC 10994/BIG 00-01 clinical trial

BACKGROUND

We have previously described gene-expression signatures that predict growth inhibitory and cytotoxic effects of common chemotherapeutic drugs in vitro. The aim of this study was to confirm the validity of these gene-expression signatures in a large series of patients with oestrogen-receptor-negative breast tumours who were treated in a phase III neoadjuvant clinical trial.

METHODS

This trial compares a non-taxane regimen (fluorouracil, epirubicin, and cyclophosphamide [FEC] for six cycles) with a taxane regimen (docetaxel for three cycles followed by epirubicin plus docetaxel [TET] for three cycles) in women with oestrogen-receptor-negative breast cancer. The primary endpoint of the study is the difference in progression-free survival based on TP53 status and will be reported later. Predicting response with gene signatures was a planned secondary endpoint of the trial and is reported here. Pathological complete response, defined as complete disappearance of the tumour with no more than a few scattered tumour cells detected by the pathologist in the resection specimen, was used to assess chemosensitivity. RNA was prepared from sections of frozen biopsies taken at diagnosis and hybridised to Affymetrix X3P microarrays. In-vitro single-agent drug sensitivity signatures were combined to obtain FEC and TET regimen-specific signatures. This study is registered on the clinical trials site of the US National Cancer Institute website http://www.clinicaltrials.gov/ct/show/NCT00017095.

FINDINGS

Of 212 patients with oestrogen-receptor-negative tumours assessed, 87 patients were excluded. 125 oestrogen-receptor-negative tumours (55 that showed pathological complete responses) were tested: 66 in the FEC group (28 that showed pathological complete responses) and 59 in the TET group (27 that showed pathological complete responses). The regimen-specific signatures significantly predicted pathological complete response in patients treated with the appropriate regimen (p<0.0001). The FEC predictor had a sensitivity of 96% (27 of 28 patients [95% CI 82-99]), specificity of 66% (25 of 38 patients [50-79]), positive predictive value (PPV) of 68% (27 of 40 patients [52-80]), and negative predictive value (NPV) of 96% (25 of 26 patients [81-99]). The TET predictor had a sensitivity of 93% (25 of 27 patients [77-98]), specificity 69% (22 of 32 patients [51-82]), PPV of 71% (25 of 35 patients [55-84]), and NPV of 92% (22 of 24 patients [74-98]). Analysis of tumour size, grade, nodal status, age, and regimen-specific signatures showed that the genomic signatures were the only independent variables predicting pathological complete response at p<0.01. Selection of patients with these signatures would increase the proportion of patients with pathological complete responses from 44% to around 70% in the patients studied here.

INTERPRETATION

We have validated the use of regimen-specific drug sensitivity signatures in the context of a multicentre randomised trial. The high NPV of both signatures may allow early selection of patients with breast cancer who should be considered for trials with new drugs.

Histopathology of breast carcinoma following neoadjuvant systemic therapy: a common association between letrozole therapy and central scarring

AIMS

Neoadjuvant systemic therapy of large and locally advanced breast cancers may, through shrinkage, enable breast conservation surgery. Letrozole, an aromatase inhibitor, is used frequently in the treatment of oestrogen receptor-positive breast cancer. The aim was to examine the response patterns in a letrozole-treated group compared with a chemotherapy-treated group.

MATERIALS AND METHODS

Fifty patients with primary breast cancer were treated with 3 months of chemotherapy and 53 with 3 months of neoadjuvant letrozole. Excised tumours were compared with preoperative core biopsy specimens. Volume calculations before and after therapy were used to calculate clinical response in the letrozole group.

RESULTS

Response patterns were significantly different between the two therapies (P < 0.0005). Chemotherapy produced more complete pathological responses (P = 0.008) and a scattered cell pattern was also seen more frequently (P = 0.035). Letrozole produced substantially more central scars - 31 cases as opposed to two cases in the chemotherapy group (P = 0.0001) - and there was a statistically significant correlation with central scarring and clinical tumour volume reduction (P = 0.034).

CONCLUSIONS

There are significantly different histological responses between cancers treated with chemotherapy and endocrine therapy, particularly central scarring. This has not been documented previously and may be an important factor in down-sizing tumours with letrozole, enabling subsequent conservation surgery.

Primary systemic therapy for operable breast cancer: A review of clinical trials and perspectives

Primary systemic therapy represents the standard of care for locally advanced breast cancer and has becoming an attractive alternative in earlier stages. A part from the proven advantage of increasing the rate of breast conservative surgery, the up front use of systemic therapy can allow for an in vivo test of treatment sensitivity, and response to primary treatment discriminates patients at different prognosis. This review will summarize the more relevant data on the preoperative treatment with chemotherapy, hormonal therapy and targeted agents.

Histopathologic assessment of tumor regression after neoadjuvant chemotherapy in advanced-stage ovarian cancer

To date, no histopathologic criteria have been established to describe treatment response after neoadjuvant chemotherapy in ovarian cancer. The aim of this study was to identify histopathologic features of tumor regression in ovarian cancer specimens obtained after neoadjuvant chemotherapy regarding their ability to indicate treatment response. This study systematically evaluated histopathologic features of tumor regression in advanced-stage ovarian cancer treated with neoadjuvant chemotherapy (n = 49) and in a control group treated with primary surgery (n = 35). In addition, the largest tumor size was measured in the surgical specimens. Overall survival served as the reference standard with a median follow-up of 49 months. There was a significantly higher presence of regressive changes in the postchemotherapy group compared with the untreated control group (P < or = .04). The presence of scattered solitary tumor cells, fibrosis, foamy macrophages, and giant cells of foreign-body type each indicated previous neoadjuvant chemotherapy with high specificity (80.0%-100%) but with low sensitivity (18.4%-63.3%). Inflammatory cell infiltrates, isolated psammoma bodies, and hemosiderin were also associated with previous chemotherapy but with lower specificity. The presence of necrosis was significantly correlated with larger tumor size within the specimens (rho = 0.5, P < .0001) and was more often found in the control group. For both groups, the extent of regressive changes, evaluated as a single parameter or in combination, showed no correlation with overall survival. However, patients with absence of residual tumor, scattered solitary tumor cells, or residual tumor foci of 5 mm or less after neoadjuvant chemotherapy had a significantly longer median overall survival of 45.6 versus 27.3 months in patients with larger tumors (P = .02). Various histopathologic features generally associated with posttreatment changes did not allow differentiation of responding from nonresponding patients and provided no prognostic information. The residual tumor size after neoadjuvant chemotherapy was the only criterion significantly correlated with treatment response and subsequent overall survival.