Radiation therapy as an adjuvant treatment after sentinel lymph node surgery for breast cancer

The detection rate of methylene blue combined with another tracer in sentinel lymph node biopsy of early-stage breast cancer: a systematic review and network meta-analysis

Background

Methylene blue (MB) alone or combined with 99mtechnetium-labeled sulphur colloid (Tc99m) or indocyanine green (ICG) is widely used for sentinel lymph node biopsy (SLNB) of early-stage breast cancer in developing countries and regions. However, studies investigating the effectiveness of MB combined with another tracer have produced heterogeneous results. The purpose of this network meta-analysis (NMA) was to evaluate the detection rate of MB alone, MB + Tc99m, and MB + ICG, and to examine the differences between the 3 methods.

Methods

We conducted a comprehensive electronic literature search on the PubMed, Embase, Web of Science, CNKI, and Wanfang Data databases from inception to October 2021. The meta-analysis included 7,498 patients in 49 studies. The risk of bias for each study was independently assessed as low, moderate, or high using criteria adapted from the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool. Fixed- and random-effects models were used to calculate pooled estimates. Mixed-comparison analysis using random-effects models. We assessed statistical heterogeneity by I2 statistics and evaluated publication bias using Begg’s test.

Results

The identification rate (IR), false-negative rate (FNR), sensitivity (SEN), and accuracy rate (AR) using MB + Tc99m were 96%, 7%, 93%, and 96%, respectively; the IR, FNR, SEN, and AR using MB + ICG were 97%, 7%, 93%, and 97%, respectively. The NMA found that IR and AR between MB + ICG and MB + Tc99m was OR =1.37 (95% CI: 0.41–4.20) and OR =1.33 (95% CI: 0.56–3.32), respectively.

Discussion

Our results are similar to those of most previous studies, and meta-analysis showed that the MB + Tc99m or MB + ICG mapping methods can be used to obtain higher IR and lower FNR than MB alone. Our NMA showed no statistical significance between MB + Tc99m and MB + ICG with IR and AR. Both MB + Tc99m and MB + ICG can be used as effective mapping methods in SLNB of early-stage breast cancer to improve the detection rate.

Angiogenesis and immune checkpoint dual blockade in combination with radiotherapy for treatment of solid cancers: opportunities and challenges

Several immune checkpoint blockades (ICBs) capable of overcoming the immunosuppressive roles of the tumor immune microenvironment have been approved by the US Food and Drug Administration as front-line treatments of various tumor types. However, due to the considerable heterogeneity of solid tumor cells, inhibiting one target will only influence a portion of the tumor cells. One way to enhance the tumor-killing efficiency is to develop a multiagent therapeutic strategy targeting different aspects of tumor biology and the microenvironment to provide the maximal clinical benefit for patients with late-stage disease. One such strategy is the administration of anti-PD1, an ICB, in combination with the humanized monoclonal antibody bevacizumab, an anti-angiogenic therapy, to patients with recurrent/metastatic malignancies, including hepatocellular carcinoma, metastatic renal cell carcinoma, non-small cell lung cancer, and uterine cancer. Radiotherapy (RT), a critical component of solid cancer management, has the capacity to prime the immune system for an adaptive antitumor response. Here, we present an overview of the most recent published data in preclinical and clinical studies elucidating that RT could further potentiate the antitumor effects of immune checkpoint and angiogenesis dual blockade. In addition, we explore opportunities of triple combinational treatment, as well as discuss the challenges of validating biomarkers and the management of associated toxicity.

Timing of determining axillary lymph node status when neoadjuvant chemotherapy is used

Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer and is a reasonable alternative to adjuvant chemotherapy for those with large operable disease. Potential clinical advantages of neoadjuvant chemotherapy include the conversion of some patients requiring mastectomy to candidates for breast-conserving surgery, the potential for downstaging axillary nodes and thus reducing the extent of axillary surgery, and the ability to correlate clinical and pathologic response to neoadjuvant chemotherapy with improved long-term outcomes. An important and controversial locoregional therapy issue in patients who are candidates for neoadjuvant chemotherapy relates to the timing of sentinel lymph node biopsy - i.e., either before or after neoadjuvant chemotherapy. This review will focus on the performance characteristics of sentinel lymph node biopsy before vs. after neoadjuvant chemotherapy and on the pros and cons of each approach.

Coverage of axillary lymph nodes in supine vs. prone breast radiotherapy

PURPOSE

To compare the dosimetry of target and normal tissue when tangents with the breast tissue were applied in a subset of breast cancer patients who had undergone computed tomography (CT) planning both supine and prone.

METHODS AND MATERIALS

The CT images of 20 patients who had undergone simulation in supine and prone positions were used for planning. The axillary lymph node regions (level I-III), breast tissue, tumor bed, heart, and bilateral lungs were manually contoured. Standard tangent fields were designed for the whole breast to deliver a prescribed dose of 50 Gy. Dose-volume histograms were compared between the two sets.

RESULTS

In each patient, coverage of breast tissue and tumor bed was readily achieved by either technique. In either position, treatment of the nodal regions was inadequate. On average, the mean dose to the nodal regions for levels I-III was approximately 50% less in the prone as compared with the supine position. The mean ipsilateral lung volume receiving 95% of the prescribed dose was 6.3% in the supine position compared to 0.43% in the prone position. When planned supine, the mean heart volume receiving 30 Gy was 0.56% compared with 0.30% in the prone position.

CONCLUSIONS

Planning in either position was found to achieve adequate coverage of the breast tissue and tumor bed for all patients. Lung was better spared prone. Coverage of axillary nodes was inadequate in either position, but further reduced in the prone vs. supine position. The choice of optimal setup should take into considerations stage and risk of nodal recurrence.

Axillary surgery in breast cancer patients

Surgeons have routinely removed ipsilateral axillary lymph nodes from women with breast cancer for over 100 years. The procedure provides important staging information, enhances regional control of the malignancy and may improve survival. As screening of breast cancer has increased, the mean size of newly diagnosed primary invasive breast cancers has steadily decreased and so has the number of women with lymph node metastases. Recognising that the therapeutic benefit of removing normal nodes may be low, alternatives to the routine level I/II axillary lymph node dissection have been sought. A decade ago sentinel lymph node biopsy (SLNB) was introduced. Because of its high accuracy and relatively low morbidity, this technique is now widely used to identify women with histologically involved nodes prior to the formal axillary node dissection. Specifically, SLNB has allowed surgeons to avoid a formal axillary lymph node biopsy in women with histologically uninvolved sentinel nodes, while identifying women with involved sentinel nodes who derive the most benefit from a completion axillary node dissection. Despite the increasing use of SLNB for initial management of the axilla in women with breast cancer, important questions remain regarding patient selection criteria and optimal surgical methods for performing the biopsy. This article discusses the evolution of axillary node surgery for women with breast cancer.

Selective Application of Axillary Node Dissection in Elderly Women with Early Breast Cancer

BACKGROUND

Routine use of axillary lymph node dissection (ALND) has been questioned in elderly women. This study examines whether selective application of ALND in early stage breast cancer affects breast cancer-related survival.

METHODS

From the Surveillance, Epidemiology, and End Results (SEER) database, records of women >or=70 years of age with stage I or II breast cancer diagnosed between 1990 and 1995 were reviewed. Hazard ratios (HR) of cause-specific survival (CSS) between women receiving ALND and those who did not were compared. To minimize the potential for bias in the selection of women to receive ALND, HR of CSS was compared within propensity analysis deciles.

RESULTS

20,151 women entered the analysis. Median follow up was 6 years (interquartile range 4.33-7.67 years). Seventy-five percent underwent ALND. Women with higher risk disease and younger age were more likely to undergo ALND. Five year unadjusted CSS in women who did and did not receive ALND was 92.1% and 90.6%, respectively, with a HR of 0.85, P = 0.002. Using the propensity analysis method, the adjusted HR for CSS associated with ALND was 0.89, P = 0.066.

DISCUSSION

After adjusting for differences in the probability of receiving ALND, no clinically or statistically significant difference in survival was observed among women who received ALND when compared with those who did not, although we could not account for differences in co-morbidity or use of systemic therapy between groups.

CONCLUSION

Surgeons select elderly women with early stage breast cancer for ALND with a negligible impact on CSS.

Effects of Sentinel Lymph Node Biopsy on Surgical Residency Training

Axillary node dissection (AND) is an integral part of surgical training. Sentinel lymph node biopsy (SLN) was introduced into our residency in 1997. Our purpose in this study was to evaluate the impact of SLN on AND experience. AND/SLN operative experience of residents and attendings at our residency was reviewed using resident case-logs and questionnaires from 2002 and 2005. The perception of performing and teaching AND was assessed. Thirty-three residents and 24 attendings participated. Graduating chiefs from the class of 2000 performed no SLN, which increased to 4.25 in 2002 and to 8.5 in 2005. In contrast, graduating chiefs performed 25 AND in 2000, which decreased to 16.5 in 2002 and to 13.25 in 2005. The majority of the residents felt that AND was a senior level case (56% postgraduate year [PGY] I and II and 87% PGY III–V). The majority of the residents felt that SLN was a junior level case (89% PGY I and II and PGY III–V). Fifty-six per cent of PGY III–V felt that SLN introduction negatively impacted their ability to perform AND. Attendings cited 15 and 24 AND before feeling comfortable performing and teaching the procedure to a resident. Since the introduction of SLN into our residency, the number of AND has decreased, with senior residents feeling that SLN has decreased their ability to perform AND. As fewer AND are performed than our attendings cite to feel comfortable, future residents may not be competent to perform or teach AND.

Complete Endoscopic Axillary Lymph Node Dissection Without Liposuction for Breast Cancer: Initial Experience and Mid-term Outcome

AIM

To present our initial experience with complete endoscopic axillary lymph node dissection (EALND) in 4 breast cancer patients with respect to feasibility, safety, and clinical outcome.

PATIENTS AND METHODS

Between January 2003 and March 2004, 4 women consented to be treated with lumpectomy followed by complete (level I, II, and III) EALND without liposuction, at the Laparoendoscopic Unit of Athens Medical School. All 4 patients presented with a solitary breast cancer lesion smaller than 2 cm in diameter and a negative clinical and sonographic lymph node status (<1 cm).

RESULTS

All the operations were completed endoscopically in less than 70 minutes (44 to 69 min). The axillary lymph node harvest ranged between 12 and 21 nodes. No lymphedema, motor nerve damage, seroma formation, or wound complications were observed. Prolonged hospitalization, owing to persistent lymphorrhoea was required for 1 patient. During a mean follow-up of 21.3 months, 2 patients reported mild hypoesthesia-paresthesia along the upper medial part of the respective arm, whereas no tumor recurrences were documented.

CONCLUSIONS

Although partial EALND has not been established as the treatment of choice for axillary management, complete EALND seems to be a feasible and effective minimally invasive treatment modality, which could be safely applied in patients with positive sentinel node biopsy, treated in specialized centers.

Use and Limitations of a Nomogram Predicting the Likelihood of Non-Sentinel Node Involvement after a Positive Sentinel Node Biopsy in Breast Cancer Patients

After a positive sentinel lymph node (SLN) biopsy, some patients may be considered to have a very low risk of non-SLN involvement and could be candidates for axillary sparing. The aim of this study was to validate the nomogram created at the Memorial Sloan-Kettering Cancer Center (MSKCC) for the prediction of non-SLN involvement in an independent set of 140 patients with both positive SLNs and axillary dissection. The predicted proportions of positive non-SLNs were compared with the observed percentages of non-SLN metastasis. Although the SLN metastasis size and tumor size did influence the risk of non-SLN involvement, the correlation between the predicted and observed proportions was weaker for our patients (R: 0.84) than for the patients assessed at the MSKCC (R: 0.97). Differences were noted in the intraoperative assessment and in the final histology of the SLNs (imprints vs frozen sections and more detailed vs less detailed, respectively), and these could partly explain the lower level of the correlation. The nomogram could not be validated and was found to be of only limited use for the prediction of non-SLN involvement in patients operated on under similar, though not fully identical conditions. We therefore warn against the unvalidated use of this prediction tool.