Current controversies in breast cancer management

Selective sentinel node biopsy after intratumour administration of radiotracer in breast cancer patients treated with neoadjuvant chemotherapy in relation to the level of tumour response

PURPOSE

Our objective was to analyse the accuracy of the sentinel node biopsy, taking into consideration the scintigraphy detection rate after the intratumoural administration of the radiopharmaceutical in patients with breast cancer who received neoadjuvant chemotherapy.

MATERIALS AND METHODS

The study included 60 patients with a diagnosis of invasive breast carcinoma, stage T1-T3, who received treatment with neoadjuvant chemotherapy, and were subsequently subjected to breast surgery and sentinel node biopsy after intra-tumour administration of the radiopharmaceutical.

RESULTS

Scintigraphic detection of some sentinel node was achieved in 55/60 patients (91.6%). When those cases that received a second injection of the radiopharmaceutical, performed peri-areolarly due to a lack of tracer migration, were excluded, the detection rate dropped to 70% (42/60). When the detection of sentinel node, or its absence, was compared in those 42 patients, no differences were found with age, laterality-location of the lesion, size pre- and post-neoadjuvant chemotherapy, histological grade, or immunohistochemical profile. There were significant differences when comparing the groups according to the degree of pathological tumour response, both with the Miller-Payne system (non-detection 44.4%-detection 16.7%, p = 0.003) as well as the residual cancer burden (72.2%-28.6%, p<0.01).

CONCLUSIONS

The scintigraphic detection of the sentinel node after intratumoural administration of the radiopharmaceutical in patients with breast cancer who received neoadjuvant chemotherapy was below the optimal value, and sometimes a further, peri-areolar, injection was necessary, probably in relation to an alteration in the lymphatic drainage pathways. There was a significant inverse relationship between the detection of the sentinel node and level of pathological tumour response.

Preoperative lymphoscintigraphy and tumor histologic grade are associated with surgical detection of the sentinel lymph node

OBJECTIVE

To study which variables involved in the process of selective sentinel node biopsy (SSNB) influence the intraoperative detection of the sentinel lymph node.

MATERIAL AND METHODS

This was a prospective cross-sectional study in 210 patients (mean age, 54 years) diagnosed with breast cancer who underwent SSNB. We recorded clinical, radiological, radioisotope administration, surgical, and histological data as well as follow-up data. We did a descriptive analysis of the data and an associative analysis using multivariable regression.

RESULTS

Deep injection alone was the most common route of radioisotope administration (72.7%). Most lesions were palpable (57.1%), presented as nodules (67.1%), measured less than 2 cm in diameter (64.8%), were located in the upper outer quadrant (49.1%), were ductal carcinomas (85.7%), were accompanied by infiltration (66.2%), and had a histologic grade of differentiation of ii (44.8%). Preoperative scintigraphy detected the sentinel node in 97.6% of cases and 95.7% were detected during the operation. One axillary relapse was observed. In the associative study, the variables "preoperative lymphoscintigraphy" and "histologic grade of differentiation of the tumor" were significantly associated with the detection of the sentinel lymph node during the operation.

CONCLUSION

The probability of not detecting the sentinel lymph node during the surgical intervention is higher in patients with high histologic grade tumors or in patients in whom preoperative lymphoscintigraphy failed to detect the sentinel node.

Breast cancer treatment beliefs and influences among surgeons in areas of scientific uncertainty

BACKGROUND

Breast cancer treatment beliefs in areas of scientific uncertainty may contribute to widely variable practices. We sought to better describe surgeons' beliefs and to identify the relative importance of different information sources on surgeons' decision-making.

METHODS

A total of 2,188 American College of Surgeons (ACoS) members were surveyed on their treatment beliefs in 4 controversial areas and on the perceived influence of various information sources on their decision-making. Responses were analyzed by sex, practice type, oncology training, professional society membership, and breast cancer patient volume.

RESULTS

Nine hundred twenty-three responses were received, with 459 eligible for analysis. Responses diverged most regarding significance of positive sentinel lymph node biopsy (SNLB) and role of post-lumpectomy radiation for low-risk ductal carcinoma-in-situ (DCIS). Overall, expert opinion ranked as the most influential information source.

CONCLUSIONS

Axillary dissection after positive SLNB and post-lumpectomy radiation in low-risk DCIS denoted areas of greater uncertainty. Breast cancer opinion leaders have substantial influence when standard practice is uncertain.

Hormonal interventions to prevent hormonal cancers: breast and prostate cancers

In 1998, the concept of breast cancer prevention became a reality with the approval of tamoxifen to reduce the risk of developing breast cancer in women at increased risk for the disease. This approval was based on decades of research on selective estrogen receptor modulators providing an understanding of the role of the estrogen receptor in breast cell growth, and an appreciation of the carcinogenic process. Although results from the Breast Cancer Prevention Trial demonstrated a 49% reduction in breast cancer in women at increased risk, there were associated toxicities related to the estrogenic effects of tamoxifen; that is, deep vein thrombosis, pulmonary embolism, and endometrial cancer. In an effort to improve its benefit-risk profile, tamoxifen is now being compared with raloxifene, a selective estrogen receptor modulator approved for the treatment and prevention of osteoporosis. This equivalency prevention Study of Tamoxifen and Raloxifene completed accrual of 19 747 high-risk postmenopausal women in November 2004. Meanwhile, another class of estrogen-directed drugs, the aromatase inhibitors, have shown efficacy in breast cancer adjuvant trials, spawning a number of prevention trials that have recently been initiated. As with breast cancer the hormonal contribution to prostate carcinogenesis was the basis for the Prostate Cancer Prevention Trial which showed that finasteride, an androgen antagonist, reduces the incidence of prostate cancer compared to placebo.

Clinical outcome and cosmesis in African-American patients treated with conservative surgery and radiation therapy

PURPOSE

The purpose of this study was to evaluate the prognostic significance of race in breast cancer patients treated with lumpectomy and radiation therapy.

METHODS AND MATERIALS

Between 1973 and 1997, 1614 patients were treated with lumpectomy and radiation therapy at our institution. All patient data, including race, age, stage, pathology, treatment, and outcome variables, were entered into a computerized database. One hundred and one women were identified as African American, and 1513 were identified as white. A small number (22) of patients of Asian, Hispanic, or other ethnic groups were eliminated from analysis. A detailed cosmetic analysis was performed on a selected subset of 20 African-American patients and 20 white patients from the database. The two groups were intentionally matched by age, follow-up, adjuvant therapy, and breast size and were asked to participate in a detailed cosmetic evaluation.

RESULTS

As of September 2001, median follow-up was 14.5 years. African-American patients presented with an earlier age of onset than white patients (51.1 African-American patients vs 56.5 white). By age groups, 42.5% of African-American patients were older than 50 years, compared with 68.6% of white patients. African-American patients presented with larger tumors (mean pathological size, 1.87 cm in African-American patients vs 1.57 cm in white patients) and were more frequently estrogen receptor negative (51% estrogen receptor-negative African-American patients vs 37% estrogen receptor-negative white patients). However, nodal status was similar in the two populations (27% node-positive African-American patients vs 24% node-positive white patients). Given their younger age and estrogen receptor negativity, African-American patients were more likely to receive chemotherapy, whereas white patients were more likely to receive adjuvant tamoxifen. Despite the earlier age of onset and larger tumor size, there were no significant differences between the African-American and white populations with respect to overall survival (82% in the African-American population vs 79% in the white) or cause-specific survival at 10 years (88% in the African-American population vs 86% in the white). African-American patients had a significantly lower breast relapse-free rate at 10 years (81% in the African-American population vs 87% in the white). Although this may be in part related to the younger age in the African-American patients, a multivariate analysis including age, race, margin status, and treatment parameters revealed young age and African-American race to be significantly associated with local relapse. With respect to overall cosmetic outcome and all specific cosmetic measures (edema, fibrosis, and pigmentation), African-American patients fared more poorly than white patients. Overall cosmesis was good to excellent in 55% of African Americans, compared with 90% of whites.

CONCLUSIONS

Despite a younger age of onset and a larger tumor size, outcome in African-American patients was similar to that of white patients with respect to overall and cause-specific survival. The explanation for a slightly higher local relapse rate and poorer cosmetic result requires further investigation.

The mechanisms of lipoxygenase inhibitor-induced apoptosis in human breast cancer cells

Previous experimental studies have shown that high dietary fat intake is associated with mammary carcinogenesis. In the current study, the effect of 5-LOX or 12-LOX inhibitors on human breast cancer cell proliferation and apoptosis, as well as the possible mechanisms were investigated. The LOX inhibitors, NDGA, Rev-5901, and baicalein all inhibited proliferation and induced apoptosis in MCF-7 (ER+) and MDA-MB-231 (ER-) breast cancer cell in vitro. In contrast, the LOX products, 5-HETE and 12-HETE had mitogenic effects, stimulating the proliferation of both cell lines. These inhibitors also induced cytochrome c release, caspase-9 activation, as well as downstream caspase-3, caspase-7 activation, and PARP cleavage. LOX inhibitor treatment also reduced the levels of anti-apoptotic proteins Bcl-2 and Mcl-1 and increased the levels of the pro-apoptotic protein bax. In conclusion, blockade of both 5-LOX and 12-LOX pathways induces apoptosis in breast cancer cells through the cytochrome c release and caspase-9 activation, with changes in the levels of Bcl-2 family proteins.