False-negative sentinel lymph node biopsy

Incidental axillary dose delivery to axillary lymph node levels I-III by different techniques of whole-breast irradiation: a systematic literature review

BACKGROUND AND OBJECTIVE

In breast cancer treatment, radiotherapy is an essential component for locoregional management. Axillary recurrence in patients with invasive breast carcinoma remains an issue. The question of whether breast irradiation may unintentionally include levels I, II, and III, and may decrease the risk of axillary recurrence, remains a topic of discussion.

PATIENTS AND METHODS

A literature search was performed in PubMed and the Cochrane Library to identify articles that have published data regarding dose-volume analysis of axillary levels in breast irradiation. The following MESH terms were used: "breast cancer/lymph nodes" AND "radiotherapy dosage."

RESULTS

Thirteen articles were identified. The irradiation technique, initial dose prescribed to the breast, delineated volumes, and dose received at axillary levels were heterogeneous. The average dose delivered to axilla levels I, II, and III with three-dimensional conformal radiotherapy using standard fields (ST) ranged between 22 and 43.5 Gy, 3 and 35.6 Gy, and 1.0 and 20.5 Gy, respectively. The average doses delivered to axilla levels I, II, and III with three-dimensional conformal radiotherapy using "high tangential" fields (HT) ranged between 38 and 49.7 Gy, 11 and 47.1 Gy, and 5 and 44.7 Gy, respectively. Finally, the average doses delivered to axilla levels I, II, and III using intensity-modulated radiation therapy (IMRT) were between 14.5 and 42.6 Gy, 3.4 and 35 Gy, and 1.2 and 25.5 Gy, respectively.

CONCLUSION

Our literature review suggests that the incidental dose delivered to the axilla during whole-breast irradiation is heterogenous and dependent on the irradiation technique used. However, whether this observation can be translated into a therapeutic effect is still a matter of debate.

[Diffusion prophylactic axillary irradiation in breast cancer - Literature review]

PURPOSE

In breast cancer, radiotherapy is an essential component of the treatment. However, indications of irradiation of the internal mammary chain and axillary area are debatables. Axillary recurrence in patients with invasive breast carcinoma remains an issue. Currently, the substitution of axillary lymph node dissection by sentinel node biopsy leads to revisit the role of axillary irradiation. Breast irradiation including level I, II and III might decrease the risk of axillary recurrence.

MATERIAL AND METHODS

A literature search was performed in PubMed and the Cochrane library to identify articles publishing data regarding dose-volume analysis of axillary levels in breast irradiation aiming to determine the potential therapeutic implications.

RESULTS

Eleven articles were retained. A total of 375 treatment plans were analyzed. The results concerning the irradiation technique, initial dose prescribed to breast, delineated volumes and dose received at axillary levels were heterogeneous. The average dose delivered to axilla levels I-III with 3D-conformal radiotherapy using standard fields were between 24Gy and 43.5Gy, 3Gy and 32.5Gy and between 1.0Gy and 20.5Gy respectively. The average doses delivered to axilla levels I-III with 3D-conformal radiotherapy using high tangential fields were between 38Gy and 49.7Gy, 11Gy and 47.1Gy and 5Gy 38.7Gy, 32.1Gy and 5Gy (result available for only one study) respectively. Finally, the average doses delivered to axilla levels I-III with intensity modulated radiation therapy were between 14.5Gy and 42.6Gy, 3.4Gy and 35Gy and between 1.2Gy and 25.5Gy respectively.

CONCLUSIONS

Incidental axillary dose seems insufficient to be therapeutic regardless of the irradiation technique. There are meaningful differences between intensity modulated radiation therapy and 3D-conformal radiotherapy.

Quantifying the Mitigating Effects of Whole-Breast Radiotherapy and Systemic Treatments on Regional Recurrence Incidence Among Breast Cancer Patients

Background

Despite the potential for residual lymph node metastases after a negative or positive sentinel lymph node biopsy (SLNB), breast cancer patients rarely experience regional recurrences (RRs). This study aimed to quantify the effects of nonsurgical treatments on RR incidence among SLNB-negative (SLNB N0) breast cancer patients.

Methods

All primary SLNB N0-staged breast cancer patients with a diagnosis between 2005 and 2008 and 5-year follow-up data on recurrences were selected from the Netherlands Cancer Registry. The cumulative incidence function (CIF) for RR was calculated as the first event at 5 years, taking into account any other first-event (local or distant recurrence, contralateral breast cancer, or death) as competing risk. Cox regression analysis was used to model the cause-specific hazard of RR developing as the first event to quantify the effect of adjuvant systemic therapy and whole-breast radiotherapy (RT) on RR incidence at 5 years.

Results

The study included 13,512 patients. Of these patients, 162 experienced an RR. The CIF of RR at 5 years was 1.3% (95% confidence interval [CI], 1.1–1.5%), whereas the CIFs for death and other events were 4.4% and 9.5%, respectively. Cox regression analysis showed hazard ratios (HRs) of 0.46 (95% CI 0.33–0.64), 0.31 (95% CI 0.18–0.55), and 0.40 (95% CI 0.24–0.67) respectively for patients treated by RT as a routine part of breast-conserving therapy (BCT), chemotherapy, and hormonal therapy.

Conclusion

RT as routine part of BCT, chemotherapy, and hormonal therapy independently exerted a mitigating effect on the risk for the development of RR. The three methods at least halved the risk.

Electronic supplementary material

The online version of this article (10.1245/s10434-020-08356-2) contains supplementary material, which is available to authorized users.

Regional Recurrence Risk Following a Negative Sentinel Node Procedure Does Not Approximate the False-Negative Rate of the Sentinel Node Procedure in Breast Cancer Patients Not Receiving Radiotherapy or Systemic Treatment

BACKGROUND

Although the false-negative rate of the sentinel lymph node biopsy (SLNB) in breast cancer patients is 5-7%, reported regional recurrence (RR) rates after negative SLNB are much lower. Adjuvant treatment modalities probably contribute to this discrepancy. This study assessed the 5-year RR risk after a negative SLNB in the subset of patients who underwent breast amputation without radiotherapy or any adjuvant treatment.

METHODS

All patients operated for primary unilateral invasive breast cancer between 2005 and 2008 were identified in the Netherlands Cancer Registry. Patients with a negative SLNB who underwent breast amputation and who were not treated with axillary lymph node dissection, radiotherapy, or any adjuvant systemic treatment were selected. The cumulative 5-year RR rate was estimated by Kaplan-Meier analysis.

RESULTS

A total of 13,452 patients were surgically treated for primary breast cancer and had a negative SLNB, and 2012 patients fulfilled the selection criteria. Thirty-eight RRs occurred during follow-up. Multifocal disease was associated with a higher risk of developing RR (P = 0.04). The median time to RR was 27 months and was significantly shorter in patients with estrogen receptor-negative (ER-) breast cancer (9.5 months; P = 0.003). The 5-year RR rate was 2.4% in the study population compared with 1.1% in the remainder of 11,440 SLNB-negative patients (P = 0.0002).

CONCLUSIONS

Excluding the effect of radiotherapy and systemic treatment resulted in a twofold 5-year RR risk in breast cancer patients with a tumor-free SLNB. This 5-year RR rate was still much lower than the reported false-negative rate of the SLNB procedure.

[Metastases in patients with breast cancer despite of negative sentinel lymph node. Has the concept to be changed?]

The sentinel lymph node (SLN) is of considerable prognostic relevance, because extended lymph node dissection may not be performed in patients presenting with histologically negative SLN. The aim of this study was to prove the prognostic value of the SLN-concept in these patients in long term follow-up.

PATIENTS, METHODS

The clinical follow-up of 202 women with histologically proven breast cancer and metastatically uninvolved (negative) SLN, as determined using Tc-99m-nanocolloid, was observed for a mean period of 43.4 months. Histological examination included standard methods (HE-Test) and special histochemical techniques (antibodies against cytokeratin). All patients underwent clinical examinations and mamography according a standardised schema; other procedures like ultrasound examination, routine blood tests, and chest X-ray scans were performed in patients considered doubtful after clinical examination or mamography.

RESULTS

Despite of negative SLN-findings in 14/202 patients (6.9%) metastases were found after a mean time period of 35.9 months. 4 patients showed local re-lapses, 3 patients presented with regional lymph node recurrences in the previously mapped (negative) SLN-basin, and 7 Patients developed distant metastases outside the primary lymphatic basin.

CONCLUSION

In patients negative on SLN-biopsy the axillary lymph-node-recurrence-rate was low; in 3/202 patients (1.5%) a progression in the SLN-basin could be assessed, being real concept failures. Our results underline that there is no evidence to question this concept in patients presented with clinically metastatically uninvolved early stage of breast cancer.

Systematic review of the effect of external beam radiation therapy to the breast on axillary recurrence after negative sentinel lymph node biopsy

BACKGROUND

Axillary recurrence after negative sentinel lymph node biopsy (SLNB) in patients with invasive breast carcinoma remains a concern. Previous investigations to identify prognostic factors for axillary recurrence identified that a disproportionate number of patients with an axillary recurrence after negative SLNB were not treated with external beam radiation therapy (EBRT) of the breast as part of initial treatment. This finding prompted a systematic review to test the hypothesis that EBRT to the breast reduces the risk of axillary recurrence after negative SLNB.

METHODS

A literature search was performed in PubMed, the Cochrane Library and the Spanish-language database LILACS to identify articles publishing data regarding follow-up of sentinel lymph node (SLN)-negative patients. Reports and articles lacking information on the initial treatment were excluded.

RESULTS

Forty-five articles were accepted for review. A total of 23,357 SLN-negative patients were identified with median follow-up ranging from 15 to 102 months. Some 18,878 patients were treated with EBRT to the breast as part of their initial treatment. One hundred and twenty-seven patients with an axillary recurrence were identified, of whom 73 had EBRT as part of their initial treatment. Meta-analysis showed that EBRT was associated with a lower rate of axillary recurrence (P < 0·001), but this finding was subject to heterogeneity.

CONCLUSION

This review and meta-analysis showed that EBRT is associated with a significantly lower axillary recurrence rate after negative SLNB.

[Axillary recurrences after sentinel lymph node biopsy in initial breast cancer]

OBJECTIVE

The aim of our study was to analyze the application of the Selective Sentinel Lymph Node Biopsy (SLNB) in early Breast Cancer of our population, through the analysis of axillary recurrences in patients with false negative sentinel node procedures without complete axillary lymphadenectomy, after a subsequent clinical follow-up.

MATERIAL AND METHODS

A total of 218 early Breast Cancer patients who underwent SLNB after being diagnosed of early breast cancer (T1-2N0) with complete axillary dissection only when the SLNB was positive in the histopathological analysis. In every case, a 2-day protocol was used to localize the sentinel node after injection of (⁹⁹m)Tc-Nanocolloid.

RESULTS

The mean subsequent clinical follow-up was 27 months. A total of 413 sentinel nodes were removed with a median of 1.89/p (range 1-5). Infiltration was detected in 33.9% of patients (59.45% macrometastasis, 22.97% micrometastasis and 17.5% Isolated Tumor Cells (ITC)) and negative for the other nodes excised after conventional lymphadenectomy in 60% of cases. In our population, there was only one case of false negative (FN) SLN due to massive lymphatic blockage, and an abnormal lymph node without uptake adjacent to the SLN was identified intraoperatively. No case of axillary recurrence was detected during an average follow-up of 27 months.

CONCLUSION

The absence of axillary recurrences in our population with negative SLNB without complete axillary dissection demonstrates the appropriate local control offered by this procedure in early Breast Cancer.

Sentinel lymph node biopsy in breast cancer: a comprehensive literature review

Sentinel lymph node biopsy has emerged as the new standard of care for nodal staging in early-stage breast disease. In the this review, the procedure of SLNB in breast cancer will be examined in greater detail with the aim of understanding techniques that may improve results and of identifying future research questions in this field.

Sentinel node biopsy in breast cancer patients with large or multifocal tumors

BACKGROUND

The axillary recurrence (AR) rate after negative sentinel node biopsy (SNB) in patients with high risk of axillary metastases is largely unknown. The aim of this study was to analyze the risk factors for isolated AR after negative SNB with special interest in large or multifocal tumors.

METHODS

A prospective SNB registry was analyzed for 2,408 invasive breast cancer patients operated between 2001 and 2007. No axillary clearance was performed in 1,309 cases with a negative SNB, including 1,138 small unifocal tumors, 121 small multifocal tumors, 48 large unifocal tumors, and 2 large multifocal tumors.

RESULTS

Six (0.5%) isolated AR were observed during a median follow-up of 43 months. Four (0.4%) patients with small unifocal tumors and two (1.6%) with small multifocal tumors had isolated AR (p = 0.179). None of the patients with large unifocal or multifocal tumors had isolated AR. Instead of tumor size and multifocality, estrogen receptor negativity (p < 0.001), nuclear grade III (p < 0.001), Her-2 status (p = 0.002), no radiotherapy (p = 0.005), and mastectomy (p = 0.005) were found to be associated with AR.

CONCLUSIONS

A remarkable proportion of patients with large unifocal tumors and small multifocal tumors may avoid unnecessary AC due to tumor negative SNB, without an excessive risk of AR.