Primary tumor response to induction chemotherapy as a predictor of histological status of axillary nodes in operable breast cancer patients

Significance of Residual Nodal Disease in Clinically Node-Negative Breast Cancer After Neoadjuvant Chemotherapy

BACKGROUND

Trials evaluating omission of axillary dissection (ALND) in patients with cN0 breast cancer with positive sentinel lymph nodes (SLNs) have excluded neoadjuvant chemotherapy (NACT). It remains unclear whether the data can be extrapolated to cN0 patients undergoing NACT. This study sought to identify factors associated with positive SLNs and additional disease on ALND in cT1-2N0 disease after NACT.

METHODS

The authors queried their database for cT1-2N0 patients treated with NACT followed by SLN biopsy from 1996 to 2022. Physical examination and ultrasound determined clinical nodal status. Multivariable logistic regression identified factors associated with positive SLNs and disease on ALND.

RESULTS

Of 1930 patients, 234 (12.1%) had positive SLNs. Positive SLNs were predicted by hormone receptor-positive (HR+)/human epidermal growth factor receptor 2-negative (HER2-) status (odds ratio [OR] 2.5; p < 0.0001), lobular histology (OR 1.8; p = 0.007), multifocality (OR 2; p = 0.001), grade 1 tumors (OR 2.5; p = 0.002), and cT2 category (OR 1.9; p = 0.004). Of the 234 patients with positive SLNs and known SLN metastasis size, 148 (63.2%) underwent ALND, and 39 (26.4%) had additional positive nodes. Increasing patient age predicted disease on ALND (OR 1.03; p = 0.02). No additional positive nodes on ALND were identified in patients with only isolated tumor cells compared with 12.3% who had micrometastases and 37.6% who had macrometastases (p = 0.01). During a 5-year median follow-up period of the SLN-positive patients, three (1.3%) experienced axillary recurrence and two of the three underwent ALND at the initial surgery with no additional positive nodes.

CONCLUSIONS

In cT1-2N0 breast cancer, HR+/HER2- status, lobular histology, multifocality and cT2 category predicted positive SLNs after NACT. Older age predicted positive nodes on ALND. Patients with positive SLNs had low axillary recurrence rates. These findings support investigation into omission of ALND in cN0 breast cancer and a low volume of SLN disease after NACT.

Should Radiotherapy after Primary Systemic Therapy be Administered with the Same Recommendations Made for Operable Breast Cancer Patients who Receive Surgery as first Treatment? A Critical Review

Primary systemic therapy is not only used in patients with locally advanced inoperable non-metastatic breast cancer but also for operable stage II and III cancer aimed at breast conservation. The indications for local-regional radiotherapy for patients who receive primary systemic therapy are still evolving. The purpose of this article is to provide a comprehensive discussion of how primary systemic therapy in operable breast cancer patients could affect the indications of radiotherapy to optimize local-regional treatment. An overview of available literature data regarding neoadjuvant treatment and radiotherapy is analyzed and discussed. Considering the variability of data on this issue, an appropriate approach could still be to tailor treatment decision to the individual clinical case.

Relationship of clinical and pathologic nodal staging in locally advanced breast cancer: current controversies in daily practice?

Systemic neo-adjuvant therapy plays a primary role in the management of locally advanced breast cancer. Without having any negative effect in overall survival, induction chemotherapy potentially assures a surgery approach in unresectable disease or a conservative treatment in technically resectable disease and acts on a well-vascularized tumor bed, without the modifications induced by surgery. A specific issue has a central function in the neo-adjuvant setting: lymph nodes status. It still represents one of the strongest predictors of long-term prognosis in breast cancer. The discussion of regional radiation therapy should be a matter of debate, especially in a pathological complete response. Currently, the indication for radiotherapy is based on the clinical stage before the surgery, even for the irradiation of the loco-regional lymph nodes. Regardless of pathological down-staging, radiation therapy is accepted as standard adjuvant treatment in locally advanced breast cancer.

Study of tumour cellularity in locally advanced breast carcinoma on neo-adjuvant chemotherapy

BACKGROUND

Breast cancer is the most common invasive malignancy which occurs in women worldwide. The advent of neoadjuvant chemotherapy has radically changed the management of locally advanced breast cancer and a complete response is reported to significantly improve disease free survival. Traditionally, clinical response is assessed on basis of tumour size. In this study, an attempt was made to check whether tumour cellularity could be a better prognostic factor and also to check as to what impact the correlation of tumour size with cellularity had on the response assessment in locally advanced breast cancer patients.

MATERIALS AND METHODS

Thirty seven patients with locally advanced breast cancer, who were treated by neoadjuvant chemotherapy during the period of December 2008 to May 2009, were selected for the study and from their case records, tumour size, clinical response and demographic details were gathered. Tumour cellularity was assessed prior to chemotherapy in core needle biopsy sections and it was matched with that seen in subsequent mastectomy specimens. Tumour size and cellularity were then correlated with the different treatment response groups and they were statistically analyzed by using the SPSS, version 13.0 software.

RESULTS

After neoadjuvant chemotherapy, the tumour size and cellularity were found to be significantly reduced in breast carcinomas (p<0.05, paired t-test). The relative changes in cellularity which were seen were highly variable between individual patients and different clinical response groups, particularly in the partial response and no response categories. The product of cellularity and size dramatically changed the distribution of residual tumour pathology, thus causing a shift towards a complete response.

CONCLUSION

The current study showed that the product of tumour size and cellularity may be a better prognostic indicator of clinical response in patients with neoadjuvant chemotherapy treated locally advanced breast cancer and that it would enable a new definition for clinical response in the future.

Axillary sentinel node biopsy after neoadjuvant chemotherapy

INTRODUCTION

The role of sentinel lymph node biopsy (SLNB) in patients with locally advanced breast cancer (LABC) with potentially sterilized axillary lymph nodes after neoadjuvant chemotherapy (NAC) remains unclear.

PATIENTS AND METHODS

Between 2002 and 2008, SLNB with both blue-dye and radioisotope injection was performed in 77 patients with LABC whose cytopathologically confirmed positive axillary node(s) became clinically negative after NAC. Factors associated with SLN identification and false-negative rates, presence of non-sentinel lymph node (non-SLN) metastasis were analyzed retrospectively.

RESULTS

SLNB was successful in 92% of the patients. Axillary status was predicted with 90% accuracy and a false-negative rate of 13.7%. Patients with residual tumor size >2 cm had a decreased SLN identification rate (p=0.002). Axillary nodal status before NAC (N2 versus N1) was associated with higher false-negative rates (p=0.04). Positive non-SLN(s) were more frequent in patients with multifocal/multicentric tumors (versus unifocal; p=0.003) and positive lymphovascular invasion (versus negative; p=0.0001). SLN(s) positive patients with pathologic tumor size >2 cm (versus <or=2 cm; p=0.004), positive extra-sentinel lymph node extension (versus negative; p=0.002) were more likely to have metastatic non-SLN(s).

CONCLUSIONS

SLNB has a high identification rate and modest false-negative rate in LABC patients who became clinically axillary node negative after NAC. Residual tumor size and nodal status before NAC affect SLNB accuracy. Additional involvement of non-SLN(s) increases with the presence of multifocal/multicentric tumors, lymphovascular invasion, residual tumor size >2 cm, and extra-sentinel node extension.

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.

Factors predicting additional disease in the axilla in patients with positive sentinel lymph nodes after neoadjuvant chemotherapy

BACKGROUND

The utility of sentinel lymph node (SNL) biopsy (SLNB) as a predictor of axillary lymph node status is similar in patients who receive neoadjuvant chemotherapy and patients who undergo surgery first. The authors of this study hypothesized that patients with positive SLNs after neoadjuvant therapy would have unique clinicopathologic factors that would be predictive of additional positive non-SLNs distinct from patients who underwent surgery first.

METHODS

One hundred four patients were identified who received neoadjuvant chemotherapy, had a positive SLN, and underwent axillary dissection between 1997 and 2005. At the time of presentation, 66 patients had clinically negative lymph nodes by ultrasonography, and 38 patients had positive lymph nodes confirmed by fine-needle aspiration. Eighteen factors were assessed for their ability to predict positive non-SLNs using chi-square and logistic regression analysis with a bootstrapped, backwards elimination procedure. The resulting nomogram was tested by using a patient cohort from another institution.

RESULTS

Patients with clinically negative lymph nodes at presentation were less likely than patients with positive lymph nodes to have positive non-SLNs (47% vs 71%; P=.017). On multivariate analysis, lymphovascular invasion, the method for detecting SLN metastasis, multicentricity, positive axillary lymph nodes at presentation, and pathologic tumor size retained grouped significance with a bootstrap-adjusted area under the curve (AUC) of 0.762. The resulting nomogram was validated in the external patient cohort (AUC, 0.78).

CONCLUSIONS

A significant proportion of patients with positive SLNs after neoadjuvant chemotherapy had no positive non-SLNs. The use of a nomogram based on 5 predictive variables that were identified in this study may be useful for predicting the risk of positive non-SLNs in patients who have positive SLNs after chemotherapy.

Neoadjuvant Systemic Therapy and the Surgical Management of Breast Cancer

Neoadjuvant chemotherapy is standard management for women who have locally advanced or inflammatory breast cancer, but can be applied to all women who may require postoperative chemotherapy for early-stage breast cancer. Disease-free survival and overall survival are equivalent between patients treated with neoadjuvant chemotherapy and patients treated with the same regimen postoperatively. Preoperative chemotherapy can offer women less morbid surgical treatment by down-staging both the primary breast tumor and axillary metastases. Finally, response to chemotherapy can inform clinicians of the chemosensitivity of the tumor, and can predict long-term outcome for women who have breast cancer.

Prognostic significance of residual breast disease and axillary node involvement for patients who had primary induction chemotherapy for advanced breast cancer

BACKGROUND

We performed this study to determine the prognostic significance of clinical tumor size, pathologic measurement of residual tumor, and number of positive axillary nodes in the surgical specimen relative to overall survival for patients who underwent primary induction chemotherapy for advanced breast cancer.

METHODS

Data, collected prospectively between 1997 and 2002, included clinical tumor-node-metastasis stage, age at diagnosis, hormone receptor status, type of preoperative chemotherapy, histological type, surgical procedure, pathologic measurement in centimeters of residual breast tumor, and the number of positive axillary nodes in the surgical specimen. Univariable correlates of residual breast disease were assessed by using the chi2 test. Recursive partitioning analysis was used to determine the prognostic significance of clinical tumor size, residual tumor size, and pathologic node involvement relative to overall survival. Survival was estimated by using the method of Kaplan and Meier and compared by using the log-rank test. A P value of <.05 was considered significant.

RESULTS

Data were available for 85 patients with advanced breast cancer. Although univariable analysis identified increasing age, clinically involved axillary nodes, and a higher clinical tumor-node-metastasis stage as predictors of an increased risk of residual disease, recursive partitioning analysis identified more than three involved axillary nodes in the surgical specimen, with or without any measurable residual breast disease, as the most significant predictor of decreased survival (P<.001).

CONCLUSIONS

Pathologic axillary node involvement was the most significant predictor of decreased survival for patients who had undergone primary induction chemotherapy for advanced breast cancer.

Role of ultrasound-guided core needle biopsy of axillary lymph nodes in the initial staging of breast carcinoma

OBJECTIVE

To evaluate the role of US-guided core biopsy in detection of metastatic axillary lymph nodes in preoperative staging of breast cancer.

MATERIALS AND METHODS

US-guided core biopsy of suspicious axillary lymph nodes was performed in 39 patients with breast cancer. Biopsy results were compared to the axillary dissection results. Sensitivity, specificity and accuracy of the core biopsy in the detection of malignancy were calculated.

RESULTS

Thirty-nine patients were assessed with biopsy; 30 patients were found to have metastatic carcinoma and nine had benign reactive hyperplasia. In 26 of 30 cases with biopsy-proven metastatic disease, there were malignant lymph nodes detected at axillary dissection. Four cases that had positive biopsy results and negative axillary dissection were accepted as complete response to chemotherapy. In three of nine cases with benign reactive hyperplasia, axillary dissection revealed metastatic disease. No significant complications were observed other than pain responding to analgesics. The sensitivity, specificity and accuracy of core biopsy in detection of malignancy were 90%, 100% and 92%, respectively. The results were statistically significant (p<0.001).

CONCLUSION

Ultrasonographically detected lymph nodes can be easily assessed by US-guided biopsy. Core biopsy is a reliable and easily performed method without significant complications.

Radiopaque coil insertion into breast cancers prior to neoadjuvant chemotherapy

Between May 1998 and December 2002, neoadjuvant chemotherapy was given to 81 women aiming to reduce tumour size and avoid mastectomy. A coil was inserted under ultrasound guidance into the tumour before treatment started. The impact of coil placement on subsequent surgery was assessed prospectively. Clinical response was seen in 69 patients and breast conservation was achieved in 60 cases. In 19 cases (23%) mammography and ultrasound were normal and localization was achieved exclusively by use of the coil. Eight of these 19 (10% of the total) had a complete pathological response; however in the remaining 11 cases (13%) there was residual invasive cancer. This study suggests that in patients undergoing neoadjuvant chemotherapy surgery is still appropriate even when clinical response appears complete. The use of the coil identifies 13% of patients with otherwise undetectable residual disease and is a valuable guide in identifying the site for further surgery.

Change in tumor cellularity of breast carcinoma after neoadjuvant chemotherapy as a variable in the pathologic assessment of response

BACKGROUND

Complete pathologic response of breast carcinoma to neoadjuvant chemotherapy is a well defined outcome that correlates with prolonged survival. Categorization of incomplete response depends on accurate measurement of residual tumor size but is complicated by the variable histopathologic changes that occur within the tumor bed. In the current study, the authors investigated the contribution of assessing tumor cellularity in the pathologic evaluation of response to chemotherapy.

METHODS

The slides from diagnostic core needle biopsy and the subsequent matched resection specimens were examined in 240 patients with breast carcinoma: 120 "treated" patients who received neoadjuvant chemotherapy and 120 "control" patients who received primary surgical management within a few weeks of diagnosis. Clinical response and residual tumor size were evaluated in 108 treated patients who completed a clinical trial with paclitaxel and then received combined 5-fluorouracil, doxorubicin, and cyclophosphamide chemotherapy. Tumor cellularity was assessed from hematoxylin and eosin-stained tissue sections as the percentage of tumor area that contained invasive carcinoma.

RESULTS

After neoadjuvant chemotherapy, tumor cellularity decreased from a median of 40% in core needle biopsy to 10% in resection specimens (P<0.01; Wilcoxon signed rank test). The cellularity of core needle biopsy (median, 30%) tended to underestimate the cellularity of resection specimens (median, 40%) in the control group (P<0.01). Changes in cellularity varied within each clinical response category, particularly partial response and minor response. The greatest reduction was observed in the cellularity of residual primary tumors that measured < or =1 cm (pathologic T1a [pT1a] and pT1b tumors), but changes in cellularity varied in the pT1, pT2, and pT3 residual tumor categories. The shape of the distribution of tumor size, expressed as the greatest dimension in cm, was similar in the control group and the treatment group (excluding complete pathologic response); however, when residual tumor size and cellularity were combined, the distribution of pathologic response shifted left (toward complete response) with a steep decline, suggesting that many tumors had a large reduction in cellularity but little change in the tumor size.

CONCLUSIONS

Cellularity of the tumor mass was reduced significantly by neoadjuvant chemotherapy, and the change varied widely in different categories of clinical response. Although residual tumors measuring < or =1 cm in greatest dimension had the most reduction in tumor cellularity, there was broad variability for all residual tumor groups (pT1-pT3). The frequency distribution of residual tumor size was altered markedly by the inclusion of tumor cellularity, indicating that the product of pathologic size and tumor cellularity may provide more accurate pathologic response information than tumor size alone.

T3 disease at presentation or pathologic involvement of four or more lymph nodes predict for locoregional recurrence in stage II breast cancer treated with neoadjuvant chemotherapy and mastectomy without radiotherapy

PURPOSE

To help define the clinical and pathologic predictors of locoregional recurrence (LRR) in breast cancer patients treated with neoadjuvant chemotherapy and mastectomy without radiotherapy for early-stage disease.

METHODS AND MATERIALS

We retrospectively reviewed the outcomes of all 132 patients with Stage I or II breast cancer treated in prospective institutional trials with neoadjuvant chemotherapy and mastectomy without radiotherapy between 1974 and 2001. The clinical stage (American Joint Committee on Cancer 1988) at diagnosis was I in 5%, IIA in 46%, and IIB in 49% of patients. The median age at diagnosis was 49 years. All patients were treated with either a doxorubicin-based neoadjuvant regimen or single-agent paclitaxel. The total LRR rates were calculated by the Kaplan-Meier method, and comparisons were made with two-sided log-rank tests. The median follow-up was 46 months.

RESULTS

The actuarial LRR rate at both 5 and 10 years was 10%. Factors that correlated positively with LRR included clinical Stage T3N0 (p = 0.0057), four or more positive lymph nodes at surgery (p = 0.0001), age < or =40 years at diagnosis (p = 0.0001), and no use of tamoxifen. In the patients who did not receive tamoxifen, estrogen receptor-positive disease correlated positively with LRR (p = 0.0067). The 5-year LRR rate for the 42 patients with clinical Stage T1 or T2 disease and one to three positive lymph nodes at surgery was 5% (only two events).

CONCLUSIONS

For patients with clinical Stage II breast cancer, T3 primary disease, four or more positive lymph nodes after chemotherapy, and age < or =40 years old predicted for LRR. For most patients with clinical T1 or T2 disease and one to three positive lymph nodes, the 5-year risk for LRR was low, and the routine inclusion of postmastectomy radiotherapy does not appear to be justified.

Preliminary outcome analysis in patients with breast cancer and a positive sentinel lymph node who declined axillary dissection

BACKGROUND

This retrospective study was designed to provide a preliminary outcome analysis in patients with positive sentinel nodes who declined axillary dissection.

METHODS

A review was conducted of patients who underwent lumpectomy and sentinel lymph node excision for invasive disease between January 1998 and July 2000. Those who were found to have sentinel lymph node metastasis without completion axillary dissection were selected for evaluation. Follow-up included physical examination and mammography.

RESULTS

Thirty-one patients were identified who met inclusion criteria. Primary invasive cell types included infiltrating ductal carcinoma, infiltrating lobular carcinoma, and mixed cellularity. Most primary tumors were T1. Nodal metastases were identified by hematoxylin and eosin stain and immunohistochemistry. Twenty-seven of the metastases were microscopic (<2 mm), and the remaining four were macroscopic. All patients received adjuvant systemic therapy. With a mean follow-up of 30 months, there have been no patients with axillary recurrence on physical examination or mammographic evaluation.

CONCLUSIONS

We have presented patients with sentinel lymph nodes involved by cancer who did not undergo further axillary resection and remain free of disease at least 1 year later. This preliminary analysis supports the inclusion of patients with subclinical axillary disease in trials that randomize to observation alone.

Prognostic value of residual node involvement in operable breast cancer after induction chemotherapy

The purpose of this retrospective study was to evaluate the influence of axillary disease on patients' survival after neoadjuvant chemotherapy and to assess patient and tumor characteristics associated with post-chemotherapy axillary involvement. After six induction cycles, 277 patients with operable breast cancer (stage II-III) underwent surgery with axillary dissection, followed by radiotherapy (n = 267) or additional chemotherapy (n = 63) and adjuvant tamoxifen therapy (n = 138). At a median follow-up of 8.5 years, overall survival (OS) and disease-free survival (DFS) were analyzed as a function of node involvement. The differences in OS and DFS according to the number of positive nodes were highly statistically significant with a decreased survival associated with the increasing number of nodes (p = 5 x 10(-6) and 9 x 10(-7), respectively). Upon multivariate analysis, the node number after chemotherapy appeared as the most significant prognostic factor (p = 7 x 10(-4) for OS and p = 3 x 10(-5) for DFS). All the other classical prognostic factors were insignificant, except post-chemotherapy Scarff-Bloom-Richardson (SBR) grading for OS (p = 8 x 10(-4)) and adjuvant hormonotherapy for DFS (p = 1 x 10(-2)). Although constituting a different parameter from primary surgery data, the number of positive nodes after chemotherapy could still remain a valuable prognostic factor at secondary surgery, raising the question for high risk patients of a second non-cross-resistant adjuvant regimen, or high dose chemotherapy with peripheral blood stem cells support.

Pathologic tumor size and lymph node status predict for different rates of locoregional recurrence after mastectomy for breast cancer patients treated with neoadjuvant versus adjuvant chemotherapy

PURPOSE

To compare the pathologic factors associated with postmastectomy locoregional recurrence (LRR) in breast cancer patients not receiving radiation who were treated with neoadjuvant chemotherapy (NEO) vs. adjuvant chemotherapy (ADJ).

METHODS AND MATERIALS

We retrospectively analyzed the rates of LRR of subsets of women treated in prospective trials who underwent mastectomy and received chemotherapy but not radiation. These trials were designed to answer chemotherapy questions. There were 150 patients in the NEO group and 1031 patients in the ADJ group. In the NEO group, 55% had clinical Stage IIIA or higher vs. 9% in the ADJ group (p <0.001, chi-square test).

RESULTS

Despite the more advanced clinical stage in the NEO group, the pathologic size of the primary tumor and the number of positive lymph nodes (+LNs) were significantly less in the NEO group than in the ADJ group (p <0.001 for both comparisons). However, the 5-year actuarial LRR rate was 27% for the NEO group vs. 15% for the ADJ group (p = 0.001, log-rank). The 5-year risk for LRR was higher in the NEO patients for all pathologic tumor sizes: 0-2 cm (18% vs. 8%, p = 0.011), 2.1-5 cm (36% vs. 15%, p <0.001), and >5 cm (46% vs. 28%, p = 0.028). The risk of LRR by the number of +LNs was similar in the NEO and ADJ groups, except for the subset of patients with > or =4 +LNs (53% vs. 23%, p <0.001). The rates of LRR in the patients with primary tumors measuring < or =2.0 cm and 1-3 +LNs were similar in both groups. However, for the patients with a pathologic tumor size of 2.1-5.0 cm and 1-3 +LNs, the LRR was higher in the NEO group than in the ADJ group (30% vs. 15%, p = 0.016). Most failures in this NEO subgroup had clinical Stage III disease. In a subset of NEO and ADJ patients matched for clinical stage, no significant differences were found in the rates of LRR according to primary tumor size and number of +LNs when these variables were analyzed independently. Again, however, differences were found in the subgroup of patients with tumors pathologically measuring 2.1-5.0 cm with 1-3 +LNs (32% NEO vs. 8% ADJ, p = 0.030).

CONCLUSION

The rates of postmastectomy LRR for any pathologic tumor size are higher for patients treated with initial chemotherapy than for patients treated with initial surgery. Radiotherapy should be offered to all patients with > or =4 +LNs, tumor size >5 cm, or clinical Stage IIIA or greater disease, regardless of whether they receive neoadjuvant or postoperative chemotherapy. The information assessing LRR rates in patients with clinical Stage II disease who receive neoadjuvant chemotherapy, particularly if 1-3 lymph nodes remain pathologically involved, is insufficient to determine whether these patients should receive radiotherapy.

Prognostic significance of a complete pathological response after induction chemotherapy in operable breast cancer

Only a few papers have been published concerning the incidence and outcome of patients with a pathological complete response after cytotoxic treatment in breast cancer. The purpose of this retrospective study was to assess the outcome of patients found to have a pathological complete response in both the breast and axillary lymph nodes after neoadjuvant chemotherapy for operable breast cancer. Our goal was also to determine whether the residual pathological size of the tumour in breast could be correlated with pathological node status. Between 1982 and 2000, 451 consecutive patients were registered into five prospective phase II trials. After six cycles, 396 patients underwent surgery with axillary dissection for 277 patients (69.9%). Pathological response was evaluated according to the Chevallier's classification. At a median follow-up of 8 years, survival was analysed as a function of pathological response. A pathological complete response rate was obtained in 60 patients (15.2%) after induction chemotherapy. Breast tumour persistence was significantly related to positive axillary nodes (P=5.10(-6)). At 15 years, overall survival and disease-free survival rates were significantly higher in the group who had a pathological complete response than in the group who had less than a pathological complete response (P=0.047 and P=0.024, respectively). In the absence of pathological complete response and furthermore when there is a notable remaining pathological disease, axillary dissection is still important to determine a major prognostic factor and subsequently, a second non cross resistant adjuvant regimen or high dose chemotherapy could lead to a survival benefit.

Minimally invasive surgery in breast cancer treatment

As genetic and biological treatment modalities are developed that can be custom-designed for individual patients, the possibility that breast cancer can be managed as a chronic long-term disease becomes more real, and the requirement for minimally invasive surgical intervention used as part of a multidisciplinary treatment approach becomes more pressing. Rather than fearing that they will be replaced, surgeons should enthusiastically move into this dynamic phase in the development of new surgical techniques for the treatment of breast cancer. This article will discuss such techniques in three evolving areas: 1) management of the axilla after neoadjuvant chemotherapy; 2) sentinel node dissection; and 3) radiofrequency ablation of primary tumors of the breast.

Neoadjuvant chemotherapy in the treatment of stage II and III breast cancer

The current attractiveness of neoadjuvant chemotherapy lies in its ability to downstage both the primary tumor and the axilla, making many patients good candidates for breast-conserving surgical techniques. This has been an important achievement in a patient group whose tumors are often considered inoperable. Attention has more recently turned to the use of neoadjuvant chemotherapy in patients with operable tumors. In patients with resectable stage II and III breast tumors, neoadjuvant chemotherapy has been demonstrated to provide effective downstaging of the primary tumor, and subsequent breast-conserving surgery results in excellent local control. In addition, neoadjuvant chemotherapy has been shown to downstage axillary lymph nodes from positive to negative in a significant number of cases. This raises the question of whether patients who have clinically negative axillae after neoadjuvant chemotherapy need to risk the morbidity associated with axillary lymph node dissection. Axillary irradiation may provide adequate regional control in patients who are clinically node negative. In addition, sentinel lymph node dissection has been shown to provide accurate assessment of the axilla in patients who have received neoadjuvant chemotherapy. An important ramification of the concept of neoadjuvant chemotherapy is that surgery that takes place after the completion of systemic therapy can become minimally invasive, accomplished in an outpatient setting without the need for an operating room suite.

Expression of LRP and MDR1 in locally advanced breast cancer predicts axillary node invasion at the time of rescue mastectomy after induction chemotherapy

BACKGROUND

Axillary node status after induction chemotherapy for locally advanced breast cancer has been shown on multivariate analysis to be an independent predictor of relapse. However, it has been postulated that responders to induction chemotherapy with a clinically negative axilla could be spared the burden of lymphadenectomy, because most of them will not show histological nodal invasion. P-glycoprotein expression in the rescue mastectomy specimen has finally been identified as a significant predictor of patient survival.

MATERIALS AND METHODS

We studied the expression of the genes encoding multidrug resistance associated protein (MDR1) and lung cancer associated resistance protein (LRP) in formalin-fixed, paraffin-embedded tumor samples from 52 patients treated for locally advanced breast cancer by means of induction chemotherapy followed by rescue mastectomy. P-glycoprotein expression was assessed by means of immunohistochemistry before treatment in 23 cases, and by means of reverse-transcriptase-mediated polymerase chain reaction (RT-PCR) after treatment in 46 (6 failed). LRP expression was detected by means of immunohistochemistry, with the LRP-56 monoclonal antibody, in 31 cases before treatment. Immunohistochemistry for detecting the expression of c-erb-B2, p53, Ki67, estrogen receptor and progesterone receptor are routinely performed in our laboratory in every case, and the results obtained were included in the study. All patients had received between two and six cycles of standard 5-fluorouracil, doxorubicin and cyclophosphamide (FAC) chemotherapy, with two exceptions [one patient received four cycles of a docetaxel-adriamycin combination, and the other four cycles of standard cyclophosphamide-methotrexate-5-fluorouracil (CMF) polychemotherapy]. Response was assessed in accordance with the Response Evaluation Criteria In Solid Tumors (RECIST). By these, 2 patients achieved a complete clinical response, 37 a partial response, and the remaining 13 showed stable disease. This makes a total clinical response rate of 75.0%. None achieved a complete pathological response.

RESULTS

MDR1 mRNA expression detected by RT-PCR was associated with the presence of invaded axillary nodes at surgery in 18/22 cases (81.8%), compared with 13/24 (54.2%) in the group with undetectable MDR1 expression. This difference was statistically significant (P < 0.05). LRP expression in more than 20% of tumor cells before any treatment was associated with axillary nodal metastasis after chemotherapy and rescue mastectomy in 17/23 cases, compared with 3/8 in nonexpressors. Again, this difference was highly significant (P < 0.01). LRP expression before treatment and MDR1 mRNA expression after treatment were significantly interrelated (P < 0.001), which might reflect the presence of chemoresistant clones liable to metastasize to the regional nodes. Persistence of previously detected MDR1-positivity after treatment (7/9 compared with 0/2 cases) was significantly associated with axillary node metastasis (P < 0.05). Finally, in a logistic regression multivariate model, histology other than ductal, a Ki67 labeling index of at least 20% and the combination of LRP and MDR1 positivity emerged as independent predictors of axillary node invasion at the time of rescue mastectomy.

CONCLUSION

The expression of different genes involved in resistance to chemotherapy, both before and after treatment with neoadjuvant, is associated with the presence of axillary node invasion at rescue surgery in locally advanced breast cancer. This might reflect the presence of intrinsically resistant clones before any form of therapy, which persist after it, and could be helpful both for prognosis and for the choice of individual treatment.