Treatment of the axilla by tangential breast radiotherapy in women with invasive breast cancer

Omitting SLNB in Breast Cancer: Is a Nomogram the Answer?

BACKGROUNDS

Sentinel lymph node biopsy (SLNB) is standard care as a staging procedure in patients with invasive breast cancer. The axillary recurrence rate, even after positive SLNB, is low. This raises serious doubts regarding the clinical value of SLNB in early breast cancer. The purpose of this study is to select patients with low suspected axillary burden in whom SLNB might be omitted.

PATIENTS AND METHODS

We retrospectively analyzed 2015 primary breast cancer patients between 2007 and 2015, with 982 patients allocated to the training and 961 to the validation cohort. Variables associated with nodal disease were analyzed and used to build a nomogram for predicting nodal disease.

RESULTS

A total of 32.8% of patients had macrometastatic disease. A predictive model was constructed based on age, cN0, morphology, grade, multifocality, and tumor size with an area under the receiver operating characteristic curve (AUC) of 0.83. Considering a false-negative rate of 5%, 32.8% of patients could be spared axillary surgery. In a subanalysis of patients with relatively favorable characteristics, 26.8% had less than 5% chance of macrometastases.

CONCLUSIONS

We present a model with excellent predictive value that can select one-third of patients in whom SLNB is deemed not necessary because of less than 5% chance of nodal involvement. Whether missing 1 in 20 patients with macrometastatic disease is worthwhile balanced against preventing side-effects of the SLN procedure remains to be established. A number of ongoing large prospective trials evaluating the outcome of omitting SLNB are awaited. Meanwhile, this nomogram may be used for individual decision-making.

Radiation dose to the low axilla in patients treated for early-stage breast cancer by locoregional intensity-modulated radiotherapy (IMRT)

PURPOSE

To determine the dose received by the low axilla during locoregional radiotherapy (RT) for early-stage breast cancer and to assess the impact of the treatment technique (three-dimensional conformal radiotherapy (3D-CRT) or rotational IMRT (VMAT) or helical tomotherapy (HT).

MATERIALS AND METHODS

The dosimetric study was performed on patients receiving normofractionated (NFRT - 50Gy in 25 fractions) or hypofractionated (HFRT - 40Gy in 15 fractions) locoregional radiotherapy (breast or chest wall and internal mammary, supraclavicular and infraclavicular nodes±axillary nodes) by 3D-CRT or VMAT or HT at the Institut Curie Paris. Patients treated by breast-conserving surgery received a boost dose of 16Gy and 10Gy to the tumour bed, respectively.

RESULTS

Sixty-eight patients treated by RT from February 2017 to January 2019 were studied. The mean dose received by the low axilla when it was not part of the target volume was 30.8Gy, 41.0Gy and 44.4Gy by 3D-CRT, VMAT and HT, respectively for NFRT and 24.2Gy, 33.0Gy and 34.9Gy, respectively, for HFRT. With NFRT, 4.1% of the axilla received 95% (V95) of the prescribed dose by 3D-CRT compared to 24.5% and 33.6% by VMAT and HT, respectively; with HFRT, V95 was 3.9%, 19.5% and 24.1%, respectively.

CONCLUSION

The axilla receives a non-negligible dose during locoregional radiotherapy; this dose is greater when VMAT or HT are used. Prospective studies must be conducted to assess the impact of this axillary dose in terms of morbidity, which currently remains unknown.

Diagnostic performance of standard breast MRI compared to dedicated axillary MRI for assessment of node-negative and node-positive breast cancer

Objectives

To investigate whether breast MRI has comparable diagnostic performance as dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer.

Methods

Forty-seven patients were included. All had undergone both breast MRI and dedicated axillary MRI, followed by surgery. All included breast MRI exams had complete field of view (FOV) of the axillary region. First, unenhanced T2-weighted (T2W) and subsequent diffusion-weighted (DW) images of both MRI exams were independently analyzed by two breast radiologists using a confidence scale and compared to histopathology. ADC values were measured by two researchers independently. Diagnostic performance parameters were calculated on a patient-by-patient basis.

Results

T2W breast MRI had the following diagnostic performance: sensitivity of 50.0% and 62.5%, specificity of 92.3%, PPV of 57.1% and 62.5%, NPV of 90.0% and 92.3%, and AUC of 0.72 for reader 1 and 0.78 for reader 2. T2W dedicated axillary MRI had the following diagnostic performance: sensitivity of 37.5% and 62.5%, specificity of 82.1% and 92.3%, PPV of 44.6% and 50.0%, NPV of 87.8% and 91.4%, and AUC of 0.65 for reader 1 and 0.73 for reader 2. In both evaluations, addition of DW images resulted in comparable diagnostic performance. For both breast MRI and dedicated axillary MRI, there was no significant difference between mean ADC values of benign and malignant lymph nodes.

Conclusions

T2W breast MRI with complete FOV of the axillary region has comparable diagnostic performance as T2W dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer. Optimization of T2W breast MRI protocol by including a complete FOV of the axillary region can, therefore, be recommended in clinical practice.

Key Points

• Breast MRI with complete field of view of the axillary region has comparable diagnostic performance as dedicated axillary MRI regarding assessment of node-negative and node-positive breast cancer.

• Optimization of breast MRI protocol by including a complete field of view of the axillary region is recommended in clinical practice.

• For both breast MRI and dedicated axillary MRI, DW imaging (including ADC measurements) is of no added value.

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.

The Adventure of Axillary Treatment in Early Stage Breast Cancer

Axillary lymph node dissection (ALND) which was an essential part of breast cancer treatment and the gold standard in evaluation of the status of axillary lymph node had notorious with increased arm morbidity and reduction of quality of life. Sentinel lymph node biopsy (SLNB) accurately stages the axilla in early breast cancer and ALND is omitted in SLNB negative patients. In patients with positive SLNB the omission of ALND with or without replacement of axillary radiotherapy has also been recommended by guidelines. The neoadjuvant chemotherapy (NAC) which has been increasingly used for large breast cancers to downstage the tumours for allowing breast conserving surgery and decreasing mastectomy rate has also been used in axillary node positive patients to reduce the need for ALND. The issues surrounding the treatment of axilla in patients treated with NAC; application and false negative rate of SLNB, number of identified sentinel lymph nodes, and axillary radiotherapy instead of ALND are currently the discussed and practiced hot topics. The quests for decreasing arm morbidity without compromising outcome in breast cancer treatment which have begun with the invention of SLNB continue for axilla conserving surgery. This article reviews the adventure of axillary treatment in breast cancer patients treated with or without NAC.

Clinically node negative breast cancer patients undergoing breast conserving therapy, sentinel lymph node procedure versus follow-up: a Dutch randomized controlled multicentre trial (BOOG 2013-08)

BACKGROUND

Studies showed that axillary lymph node dissection can be safely omitted in presence of positive sentinel lymph node(s) in breast cancer patients treated with breast conserving therapy. Since the outcome of the sentinel lymph node biopsy has no clinical consequence, the value of the procedure itself is being questioned. The aim of the BOOG 2013-08 trial is to investigate whether the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients treated with breast conserving therapy.

METHODS

The BOOG 2013-08 is a Dutch prospective non-inferiority randomized multicentre trial. Women with pathologically confirmed clinically node negative T1-2 invasive breast cancer undergoing breast conserving therapy will be randomized for sentinel lymph node biopsy versus no sentinel lymph node biopsy. Endpoints include regional recurrence after 5 (primary endpoint) and 10 years of follow-up, distant-disease free and overall survival, quality of life, morbidity and cost-effectiveness. Previous data indicate a 5-year regional recurrence free survival rate of 99% for the control arm and 96% for the study arm. In combination with a non-inferiority limit of 5% and probability of 0.8, this result in a sample size of 1.644 patients including a lost to follow-up rate of 10%. Primary and secondary endpoints will be reported after 5 and 10 years of follow-up.

DISCUSSION

If the sentinel lymph node biopsy can be safely omitted in clinically node negative breast cancer patients undergoing breast conserving therapy, this study will cost-effectively lead to a decreased axillary morbidity rate and thereby improved quality of life with non-inferior regional control, distant-disease free survival and overall survival.

TRIAL REGISTRATION

The BOOG 2013-08 study is registered in ClinicalTrials.gov since October 20, 2014, Identifier: NCT02271828. https://clinicaltrials.gov/ct2/show/NCT02271828.

Factors Associated With Disease Recurrence in Breast Cancer Patients With Negative Sentinel Lymph Node Biopsy

INTRODUCTION

The objective of our study was to assess recurrence after negative sentinel lymph node biopsy (SLNB) and to determine the risk factors related to local and distant recurrence in this group of patients.

MATERIALS AND METHODS

We conducted a prospective observational study from 2006 to 2011. It included 607 patients with early-stage breast cancer and negative SLNB with a 5-year follow-up period.

RESULTS

The disease-free survival rate was 98.5% and 96.5% at 2 and 5 years, respectively. Multivariate analysis identified the following prognostic factors for disease recurrence: tumor necrosis (hazard ratio [HR], 4.89; 95% confidence interval [CI], 1.61-14.89; P = .005), lymphovascular invasion (HR, 3.46; 95% CI, 1.14-10.55; P = .029), T2 tumor size (HR, 4.35; 95% CI, 1.40-13.52; P = .011), and moderate to severe lymphoplasmacytic stromal infiltration (HR, 3.06; 95% CI, 1.18-7.96; P = .022).

CONCLUSION

Recurrence in patients with negative SLNB was satisfactorily low. Nevertheless, determining the prognostic factors related to a greater recurrence rate could help identify high-risk patients and influence systemic adjuvant therapy.

Axillary coverage by whole breast irradiation in 1 to 2 positive sentinel lymph nodes in breast cancer patients

PURPOSE

To evaluate the dosimetric coverage of axillary levels I, II, and III obtained with standard whole breast irradiation in 1 to 2 positive sentinel lymph nodes (SLNs) patients not submitted to axillary lymph nodes dissection (ALND), and to compare the lymph nodes areas coverage obtained with 3D conformal radiation therapy, intensity-modulated radiotherapy (IMRT), and volumetric modulated arc therapy (VMAT).

METHODS

Patients with 1 to 2 positive SLNs undergoing breast-conserving therapy, without ALND, were included in the analysis. For each patient, 3 treatment plans were performed: a 3D conventional tangential plan, a static IMRT plan, and a volumetric IMRT, designed to encompass the entire breast parenchyma. The volumes of axillary levels I, II, and III receiving 90% and 95% (V90, V95) of the whole breast prescribed dose were evaluated. Dose-volume histograms were compared by means of the Friedman test.

RESULTS

Ten patients were enrolled. All defined breast volumes received >95% of the prescribed dose with the 3 techniques. Median V95 for axillary level I was 26.4% (range 4.7%-61.3%) for 3D plans, 8.6% (range 0.64%-19.1%) for static IMRT plans, and 2.6% (range 0.4%-4.7%) for volumetric IMRT plans (p<0.001). Median V95 for axillary level II was 5.4% (range 0%-14.6%), 1.9% (range 0%-15%), and 2.6% (range 0.4%-4.7%) for 3D, static IMRT, and volumetric IMRT, respectively (p<0.001).

CONCLUSIONS

Results of our analysis showed that standard 3D tangential whole breast irradiation failed to deliver a therapeutic dose to axillary levels I and II. The coverage was even lower using static and volumetric IMRT techniques.

Evaluation of Sentinel Lymph Node Dose Distribution in 3D Conformal Radiotherapy Techniques in 67 pN0 Breast Cancer Patients

Introduction. The anatomic position of the sentinel lymph node is variable. The purpose of the following study was to assess the dose distribution delivered to the surgically marked sentinel lymph node site by 3D conformal radio therapy technique. Material and Method. We retrospectively analysed 70 radiotherapy (RT) treatment plans of consecutive primary breast cancer patients with a successful, disease-free, sentinel lymph node resection. Results. In our case series the SN clip volume received a mean dose of 40.7 Gy (min 28.8 Gy/max 47.6 Gy). Conclusion. By using surgical clip markers in combination with 3D CT images our data supports the pathway of tumouricidal doses in the SN bed. The target volume should be defined by surgical clip markers and 3D CT images to give accurate dose estimations.

Three-Dimensional Breast Radiotherapy and the Elective Radiation Dose at the Sentinel Lymph Node Site in Breast Cancer

Background

Several trials are presently randomizing clinically node-negative breast cancer patients treated with breast-conserving therapy (BCT) to sentinel lymph node biopsy (SLNB) or watchful waiting. We aimed to investigate the elective radiation dose at the sentinel lymph node (SLN) site while evaluating two techniques for SLN localization, in breast cancer patients treated with lumpectomy and three-dimensional (3D) whole-breast radiotherapy.

Methods

The SLN site of consecutive Tis-2N0 breast cancer patients undergoing lumpectomy and forward intensity-modulated whole-breast radiotherapy was determined by the location of the hotspot on preoperative single-photon emission computed tomography (SPECT)/computed tomography (CT) and by a surgical clip placed at the removed SLN(s) during SLNB. The radiation dose at the SLN site was subsequently determined on the postoperative radiotherapy planning CT. An elective radiation dose to the SLN site was defined as at least 95 % of the breast dose.

Results

Of the 42 included patients, the mean percentage of the breast dose on the SLN site was 90 % (standard deviation 26, range 7–132, median 99), with a non-significant difference between the two techniques (surgical clip or SPECT/CT) (p = 0.608). In 32/42 patients (76 %) the SLN site received an elective radiation dose.

Conclusions

A surgical clip placed at the removed SLN(s) during SLNB proved to be an adequate method of determining the radiation dose at the SLN site when compared with using SPECT/CT. With the use of 3D radiotherapy, the site of the SLN is treated with an elective radiation dose in the majority of patients who are treated with BCT.

Axillary recurrence after a tumor-positive sentinel lymph node biopsy without axillary treatment: a review of the literature

Background

Sentinel lymph node biopsy (SLNB) has become standard of care as a staging procedure in patients with invasive breast cancer. A positive SLNB allows completion axillary lymph node dissection (cALND) to be performed. The axillary recurrence rate (ARR) after cALND in patients with positive SLNB is low. Recently, several studies have reported a similar low ARR when cALND is not performed. This review aims to determine the ARR when cALND is omitted in SLNB-positive patients.

Methods

A literature search was performed in the PubMed database with the search terms “breast cancer,” “sentinel lymph node biopsy,” “axillary” and “recurrence.” Articles with data regarding follow-up of patients with SLNB-positive breast cancer were identified. To be eligible, patients should not have received cALND and ARR should be reported.

Results

Thirty articles were analyzed. This resulted in 7,151 patients with SLNB-positive breast cancer in whom a cALND was omitted (median follow-up of 45 months, range 1–142 months). Overall, 41 patients developed an axillary recurrence. 27 studies described 3,468 patients with micrometastases in the SLNB, of whom 10 (0.3 %) developed an axillary recurrence. ARR varied between 0 and 3.7 %. Sixteen studies described 3,268 patients with macrometastases, 24 (0.7 %) axillary recurrences were seen. ARR varied between 0 and 7.1 %. Details regarding type of surgery and adjuvant treatment were lacking in the majority of studies.

Conclusions

ARR appears to be low in SLNB-positive patients even when a cALND is not performed. Withholding cALND may be safe in breast cancer selected patients such as those with isolated tumor cells or micrometastatic disease.

Axillary lymph node dose with tangential whole breast radiation in the prone versus supine position: a dosimetric study

Background

Prone breast positioning reduces skin reaction and heart and lung dose, but may also reduce radiation dose to axillary lymph nodes (ALNs).

Methods

Women with early stage breast cancer treated with whole breast irradiation (WBI) in the prone position were identified. Patients treated in the supine position were matched for treating physician, laterality, and fractionation. Ipsilateral breast, tumor bed, and Level I, II, and III ALNs were contoured according to the RTOG breast atlas. Clips marking surgically removed sentinel lymph nodes (SLN)s were contoured. Treatment plans developed for each patient were retrospectively analyzed. V90_% and V95_% was calculated for each axillary level. When present, dose to axillary surgical clips was calculated.

Results

Treatment plans for 46 women (23 prone and 23 supine) were reviewed. The mean V90_% and V95_% of ALN Level I was significantly lower for patients treated in the prone position (21% and 14%, respectively) than in the supine position (50% and 37%, respectively) (p < 0.0001 and p < 0.0001, respectively). Generally, Level II & III ALNs received little dose in either position. Sentinel node biopsy clips were all contained within axillary Level I. The mean V95_% of SLN clips was 47% for patients treated in the supine position and 0% for patients treated in the prone position (p < 0.0001). Mean V90_% to SLN clips was 96% for women treated in the supine position but only 13% for women treated in the prone position.

Conclusions

Standard tangential breast irradiation in the prone position results in substantially reduced dose to the Level I axilla as compared with treatment in the supine position. For women in whom axillary coverage is indicated such as those with positive sentinel lymph node biopsy who do not undergo completion axillary dissection, treatment in the prone position may be inappropriate.

[Proposal for a new multidisciplinary therapeutic strategy in the breast cancer patient with sentinel lymph node metastasis]

Sentinel lymph node (SLN) biopsy is the standard of practice for assessing axillary spread in clinically node-negative breast cancer patients. On the other hand, axillary lymph node dissection (ALND) is the ideal procedure for patients with SLN metastasis. Different studies over the last few years have suggested that some patients with positive SLN can be treated without ALND. This article presents a literature review carried out by our multidisciplinary group and its strategy for avoiding routine ALND in women with SLN metastases. In this new strategy ALND should not be performed on women with T1 tumours, with 1-2 positive SLN and undergoing breast conservative surgery. On the other hand, ALND would be indicated in those patients with three or more positive SLN, presence of extracapsular invasion, mastectomised women and triple negative subtype or HER2+ tumours that have not received biological treatment with antibodies.

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.

Treatment of breast carcinoma in patients with clinically negative axillary lymph nodes using radiotherapy versus axillary dissection

BACKGROUND

The role of axillary lymph node dissection (AxD) for patients with breast carcinoma who have clinically negative lymph nodes (cN0) and undergo breast-conserving therapy has been controversial. If patients do not undergo AxD, then it is uncertain whether specific lymph node irradiation should be given. The authors compared the results obtained from patients w ho underwent AxD with the results from patients who received axillary irradiation (AxR) using one of two radiotherapy techniques.

METHODS

Patients with T1-T2cN0 breast carcinoma were treated from 1983 to 2002 with either AxD (80 patients) or AxR (1134 patients received tangential-field [2-field] irradiation, and 303 patients received 3-field irradiation). The median follow-up was 161 months for the AxD group and 66 months for the AxR group (55 months for patients who received tangential-field irradiation, and 122 months for patients who received 3-field irradiation).

RESULTS

One patient in the AxD group and 35 patients in the AxR group had axillary recurrences. The 10-year cumulative axillary recurrence rates were 1.3% and 4.6% for the AxD group and the AxR group, respectively (P = 0.21). For patients with T1 tumors, the 10-year overall survival rates for the two groups were 94.7% and 92.7%, respectively (P = 0.34); and, for patients with T2 tumors, the 10-year overall survival rates were 92.5% and 89.1%, respectively (P = 0.34). In the AxR group, the 5-year axillary recurrence rates were 2.5% for patients who received tangential-field irradiation and 1.7% for patients who received 3-field irradiation (P = 0.18), and the 5-year regional recurrence rates for the two groups were 4.8% and 2.4%, respectively (P = 0.048). On multivariate analysis, positive lymphovascular invasion, outer tumor location, and larger tumor size were significant risk factors for regional failure.

CONCLUSIONS

For patients with cN0 breast carcinoma, AxD and AxR yielded the same overall survival rates. Most patients can be treated safely with tangential-field irradiation alone. Patients who are at increased risk of regional failure may benefit from three-field irradiation.

Factors predictive of having four or more positive axillary lymph nodes in patients with positive sentinel lymph nodes: implications for selection of radiation fields

PURPOSE

The optimal design of radiation fields for patients with positive sentinel lymph nodes (SLNs) who do not undergo axillary dissection is unknown. We have previously shown that modified breast tangent fields can include most axillary Level I-II lymph nodes. We have also reported that irradiation of the axillary apex/supraclavicular fossa is indicated for patients with four or more positive axillary lymph nodes. To determine the optimal arrangement for patients with positive SLNs, we studied what factors predicted for having four or more positive lymph nodes.

METHODS AND MATERIALS

We reviewed the records of 339 consecutive patients with one to three positive SLNs who underwent complete axillary dissection at our institution between 1995 and 2002. We separately analyzed the outcome for those initially treated with surgery (n = 265) and those receiving neoadjuvant chemotherapy (n = 74). A logistic regression model was used to identify independent factors predictive for four or more positive lymph nodes.

RESULTS

A total of 28 of 265 patients in the initial surgery group and 20 of 74 patients in the neoadjuvant group had four or more positive lymph nodes. In the initial surgery group, the independent factors associated with four or more positive lymph nodes were no drainage seen on lymphoscintigraphy (rate, 38%, odds ratio [OR] = 5.4, p = 0.03), more than one positive SLN (rate, 24-42%, OR = 2.9, p = 0.02), and lymphovascular space invasion (LVSI; rate, 25%, OR = 4.8, p = 0.01). Of the 106 patients without any of these factors, only 2 had four or more positive lymph nodes. For the patients treated with neoadjuvant chemotherapy, the independent factors were clinical Stage III (rate, 48%, OR = 3.1, p = 0.03), more than one positive SLN (rate, 37-67%, OR = 4.8, p = 0.03), and LVSI (rate, 62%, OR = 8.1, p = 0.02). Of the 28 patients without any of these factors, only 1 had four or more positive lymph nodes.

CONCLUSION

It is reasonable to treat with modified tangents fields that include most axillary Level I-II nodes for patients with one positive SLN who do not undergo axillary dissection if drainage is seen on lymphoscintigraphy and no LVSI is present. This approach is also reasonable for patients treated with neoadjuvant chemotherapy who have Stage II disease, no LVSI, and only one positive SLN. The remaining patients have a greater risk of having four or more positive lymph nodes, and, therefore, the high axilla/supraclavicular fossa should also be included in the radiation fields.

Current Controversies Concerning Sentinel Lymph Node Biopsy for Breast Cancer

BACKGROUND AND METHODS

The objectives of this article are to review existing controversies regarding sentinel lymph node (SLN) biopsy and to identify potential areas of consensus in order to eliminate routine axillary lymph node dissection (ALND).

RESULTS

A combination of peritumoral injection with radioisotopes and subdermal or subareolar injection with blue dye may result in enhanced success rates of SLN identification. Preoperative lymphoscintigraphy is most useful for detecting an internal mammary SLN, but the practicability of internal mammary SLN biopsy is still in the investigative stage. Intraoperative diagnosis of SLN is useful because patients with SLN metastases may be treated immediately with ALND, but it is unreasonable to expect that either examination of frozen sections or imprint cytology will detect every metastatic disease. SLN micrometastases may be of prognostic importance and these can be identified with H and E staining on permanent sections of 200 micro m intervals. While ALND is preferable for patients even with a small tumor (T1) and SLN micrometastases, radiation therapy is an acceptable alternative. SLN biopsy may be indicated for patients with DCIS detected as a palpable mass or those with large calcification areas in the breast. The accuracy of SLN biopsy after neoadjuvant chemotherapy is considered to be unproven.

CONCLUSION

Since SLN biopsy has been adopted by surgeons around the world, consistency of technique and case selection has attained great significance.

Conservation Therapy in T1-T2 Breast Cancer

PURPOSE

To assess the significance of patient age, race, tumor-related prognostic parameters, status of surgical excision margins, and irradiation boost on incidence of ipsilateral breast relapse, and to review current issues in the management of T1-T2 breast cancer patients with conservation therapy.

MATERIALS AND METHODS

Records of 1037 patients with histologically confirmed stage T1 and 308 patients with T2 carcinoma of the breast treated with breast conservation therapy from January 1970 through December 1997 were prospectively registered and evaluated. The mean follow-up for surviving patients was 6.6 years (range, 4-30 years), with a minimum follow up of 4 years for all patients.

RESULTS

There were 78 ipsilateral breast relapses (IBRs); the actuarial 10-year incidence of IBR was 7% for T1 and 11% for T2 tumors. In patients 40 years of age or younger, four of 24 (17%) with extensive intraductal component developed an ipsilateral breast relapse, compared with six of 80 (8%) without extensive intraductal component, in contrast to eight of 159 (5%) and 33 of 776 (4%) in postmenopausal patients with or without extensive intraductal component, respectively. In patients with T2 tumors, two of eight (25%) women 40 years or younger with extensive intraductal component, and seven of 50 (14%) without extensive intraductal component developed ipsilateral breast relapse. The corresponding values for the patients older than 40 years were five of 48 (10%) and 13 of 202 (6%), respectively. The incidences of ipsilateral breast relapses, correlated with status of surgical margins after re-excision in T1 tumors, were one of 30 (3.3%) for positive, no relapses in 40 patients with close margins, 16 of 438 (3.6%) for negative, and 18 of 196 (9%) for undetermined margins. In the patients with T2 tumors, ipsilateral breast relapses occurred in two of 16 patients (12.5%) with positive margins, one of 16 (6%) with close, seven of 105 (6.6%)with negative, and four of 68 (5.9%) with undetermined margins (differences not statistically significant). In patients with T1 tumors, negative margins, the 10-year relapse rate was the same (8%) in 559 to whom a boost was administered and in 66 without a boost. In patients with positive margins, the relapse rate was 4% in 215 receiving a boost (18-20 Gy) and 33% (two of six) without a boost. In patients with T2 tumors and negative margins, the rate of ipsilateral breast relapses in 16 patients to whom no boost was given was 12%, as opposed to 10% in 143 patients who received a boost. However, with T2 tumors and close or positive margins, the IBR rate at 10 years was 12% in 81 given a boost, in contrast to 40% (2 of 5) without a boost. In T1 tumors, the breast failure rate was two of 53 (3.7%) in women < or = 40 years receiving chemotherapy and eight of 51 (15.6%) without chemotherapy. For T2 tumors, the corresponding values were seven of 39 (17%) and two of 19 (10.5%), respectively. In women 40 years or younger with T1 tumors receiving hormones or not, the ipsilateral breast relapse rate was two of 19 (10.5%) and eight of 85 (9.4%), respectively; in the older than 40 years group, the corresponding values were six of 377 (1.6%) and 35 of 558 (6.2%). In the patients with T2 tumors, ipsilateral breast relapse rates were not statistically different in the various groups. On multivariate analysis, only age and adjuvant therapy were significant factors predictive of ipsilateral breast relapse.

CONCLUSIONS

Surgical excision margins status following adequate doses of radiation therapy was not a predictor of ipsilateral breast relapse. In patients younger than 40 years of age with extensive intraductal component, a somewhat higher breast relapse rate was noted but not enough to preclude breast conservation therapy. A boost of irradiation did not have a significant impact in the incidence of ipsilateral breast relapse in patients with negative margins, but it was of benefit to those with close or positive margins. Close attention to surgical margin status and delivery of higher doses of irradiation to the tumor excision site in patients with close or positive surgical margins will decrease the probability of breast relapses.