Is it necessary to perform prospective randomized studies before sentinel node biopsy can replace routine axillary dissection?

Axillary surgery for breast cancer: past, present, and future

In breast cancer surgery, there has been a major shift toward less invasive local treatment. Although axillary lymph node dissection (ALND) was an integral part of surgical treatment for breast cancer, sentinel lymph node (SLN) biopsy was developed as an accurate method for axillary staging. ALND can be avoided not only in patients with negative SLNs but also in those with one or two positive SLNs receiving breast and/or axillary radiation. On the other hand, ALND has remained the standard treatment for patients with clinically positive nodes. However, axillary reverse mapping (ARM) was developed to map and preserve arm lymphatic drainage during ALND and/or SLN biopsy. This procedure allowed reduction of the rate of arm lymphedema without increasing axillary recurrence, although patients receive postoperative chemotherapy and high-risk patients undergo axillary radiation. Standard ALND may not be necessary even for patients with clinically positive nodes who receive axillary radiation and systemic therapy. Thus, the extent of axillary surgery in breast cancer has been decreased with increased use of systemic and radiation therapy.

Sentinel lymph node biopsy: technique validation at the Setúbal Medical Centre, Portugal

Aims:

To evaluate the accuracy of sentinel lymph node biopsy in breast cancer patients at this institution, using combined technetium-99m (^99mTc) sulphur colloid and patent blue vital dye.

Methods:

From March 2007 to July 2008, 50 patients with a tumour of less than 3 cm and with clinically negative axillary lymph nodes underwent sentinel lymph node biopsy (SLNB), followed by axillary lymph node dissection (ALND). Sub-areolar ^99mTc sulphur colloid injection was performed the day before surgery, and patent blue vital dye was also injected sub-areolarly at least 5 minutes before surgery. Sentinel lymph node was identified during the surgical procedure, using a gamma probe and direct vision. All sentinel nodes underwent frozen section analysis. Later haematoxylin and eosin staining and immunohistochemical analysis were performed. Finally, SLNB was compared with standard ALND for its ability to accurately reflect the final pathological status of the axillary nodes.

Results:

The sentinel lymph node (SLN) was identified in 48 of 50 patients (96%). The number of sentinel lymph nodes ranged from one to four (mean 1.48) and non-sentinel nodes ranged from seven to 27 (mean 14.33). Of the 48 patients with successfully identified SLNs, 29.17% (14/48) were histologically positive. Sensivity of the SLN to predict axilla was 93.75%; accuracy was 97.96%. The SLN was falsely negative in one patient—6.25% (1/16).

Conclusions:

The SLNB represents a major advance in the surgical treatment of breast cancer as a minimally invasive procedure predicting the axillary lymph node status. This validation study demonstrates the accuracy of the SLNB and its reasonable false negative rate when performed in our institute. It can now be used as the standard method of staging in patients with early breast cancer at this institution.

Avoidance of axillary lymph node dissection in selected patients with node-positive breast cancer

AIMS

Currently, it is standard practice to avoid ALND in patients with negative SLN, whereas this procedure is mandated for those with positive SLN. However, there has been some debate regarding the necessity of complete ALND in all patients with positive SLN. This review article discusses the issues related to eliminating the need for ALND in selected patients with positive nodes.

METHODS

A review of the English language medical literature was performed using the MEDLINE database and cross-referencing major articles on the subject, focusing on the last 10 years.

RESULTS

Currently, complete ALND is mandated in patients with SLN macrometastases as well as those with clinically positive nodes. It is not clear whether SLN biopsy is appropriate for axillary staging in patients with initially clinically positive nodes (N1) that become clinically node-negative (N0) after neoadjuvant chemotherapy. Although there is debate regarding whether ALND should be performed in patients with micrometastases in the SLN, it seems premature to abandon ALND in clinical practice. Moreover, it remains unclear whether it is appropriate to avoid complete ALND in patients with ITC-positive SLN alone.

CONCLUSIONS

In the absence of data from randomised trials, the long-term impact of SLN biopsy alone on axillary recurrence and survival rate in patients with SLN micrometastases as well as those with ITC-positive SLN remains uncertain. These important issues must be determined by careful analysis of the results of ongoing clinical trials.

President’s Address

In breast cancer surgery, there has been a major shift toward less invasive local treatment: from extended or radical mastectomy to modified radical mastectomy, from modified radical mastectomy to breast conserving therapy, and from routine axillary lymph node dissection to sentinel lymph node biopsy. Many breast surgeons have experienced an evolutionary progression of surgical management of breast cancer. However, there is an increasing demand for minimally invasive and non-surgical treatment methods for patients with small breast cancer. Radiofrequency (RF) ablation is the most promising among non-surgical ablation techniques in the treatment of breast cancer, although it is still in the investigative stage. Nevertheless, surgery still plays an integral role in the treatment of breast cancer, because local therapy is important for enhancing survival in the presence of systemic therapy. In clinical practice, surgical oncologists must individualize treatments, selecting a surgical or non-surgical procedure that provides the best local control, does not compromise the chances of cure, and achieves the best cosmetic results.

Recurrence after sentinel lymph node biopsy with or without axillary lymph node dissection in patients with breast cancer

BACKGROUND

A regional nodal recurrence is a major concern after a sentinel lymph node biopsy (SLNB) alone in patients with breast cancer. In this study we investigated patterns and risk factors of regional nodal recurrence after SLNB alone.

PATIENTS AND METHODS

Between January 1999 and March 2005, a series of 1,704 consecutive breast cancer cases in 1,670 patients (34 bilateral breast cancer cases) with clinically negative nodes or suspicious nodes for metastasis who underwent SLNB at a single institute (Saitama Cancer Center) were studied. All 1,704 cases were classified based upon presence or absence of a metastatic lymph node, treated with or without axillary lymph node dissection (ALND). The site of first recurrence was classified as local, regional node, or distant. The regional node recurrences were subclassified as axillary, interpectoral, infraclavicular, supraclavicular, or parasternal.

RESULTS

After a median follow-up period of 34 months (range, 2-83 months), first recurrence occurred in local sites in 32 (1.9%) cases, regional nodes in 26 (1.5%) cases, and distant sites in 61 (3.6%) cases. In 1,062 cases with negative nodes treated without ALND and 459 cases with positive nodes treated with ALND, 11 (1.0%) and 15 (3.3%) recurred in regional nodes, respectively, and 4 (0.4%) and 2 (0.6%) recurred in axillary nodes, respectively. Of 822 cases of invasive breast cancer with negative nodes treated with SLNB alone, 10 (1.4%) recurred in regional nodes, and 4 (0.5%) recurred in axillary nodes. In the 10 patients with regional nodal failure, all of the tumors were negative for estrogen receptor (ER) and/or progesterone receptor (PR) and were nuclear grade (NG) 3.

CONCLUSIONS

The axillary recurrence rate was low in patients treated with SLNB alone. Omitting ALND is concluded to be safe after adequate SLNB. Risk factors for regional nodal failure after SLNB alone are negative hormone receptor status and high NG.

Sentinel Lymph Node Biopsy Alone Has No Adverse Impact on the Survival of Patients with Breast Cancer

We do not yet know the results from multicenter randomized trials comparing survival after sentinel lymph node biopsy (SLNB) alone and axillary lymph node dissection (ALND). Therefore, in this study, the prognostic significance of the type of axillary surgery is analyzed in combination with other known prognostic factors in patients with breast cancer. In a series of 1325 consecutive patients with unilateral breast cancer who underwent SLNB between January 1999 and June 2004 at a single institution, 884 underwent SLNB alone following an intraoperative negative histologic investigation and 441 underwent ALND. Disease-free survival (DFS) and overall survival (OS) were analyzed to correlate with clinicopathologic features and treatment methods using both univariate and multivariate analyses Cox proportional hazard regression models. With a median follow-up period of 31 months, 29 (3.3%) and 37 (8.4%) patients relapsed after SLNB alone and ALND, respectively. Tumor size (Tis, T1-2 versus T3-4), histologic nodal involvement (negative versus positive), nuclear grade (NG) (1, 2 versus 3), lymphatic vessel invasion (LVI) (absent, weak versus intense), estrogen receptor (ER) status (positive versus negative), type of axillary surgery (SLNB alone versus ALND), type of breast surgery (partial versus total mastectomy), and radiation therapy (yes versus no) significantly correlated with DFS by univariate analysis, demonstrating better DFS in the former category than the latter for each variable. The multivariate analysis revealed that NG, LVI, ER status, and radiation therapy significantly correlated with DFS, and ER and histologic nodal involvement correlated with OS. As the type of axillary surgery had no impact on the prognosis of patients with breast cancer, a SLNB alone is safe as determined by a negative histologic investigation.

Probability of axillary lymph node metastasis when sentinel lymph node biopsy is negative in women with clinically node negative breast cancer: a Bayesian approach

BACKGROUND

Although sentinel lymph node biopsy(SLNB)is highly accurate in predicting axillary nodal status in patients with breast cancer, it has been shown that the procedure is associated with a few false negative results. The risk of leaving metastatic nodes behind in the axillary basin when SLNB is negative should be estimated for an individual patient if SLNB is performed to avoid conventional axillary lymph node dissection(ALND).

METHODS

A retrospective analysis of 512 women with T1-3N0M0 breast cancer was conducted to derive a prevalence of nodal metastasis by T category as a pre-test(i.e., before SLNB)probability and to examine potential confounders on the relationship between T category and axillary nodal involvement. Probability of nodal metastasis when SLNB was negative was estimated by means of Bayes' theorem which incorporated the pre-test probability and sensitivity and specificity of SLNB.

RESULTS

Axillary nodal metastasis was observed in 6.1% of T1a-b, 25.1% of T1c, 28.7% of T2, 35.0% of T3 tumors. Point estimates for the probability of nodal involvement when SLNB was negative ranged from 0.3-1.3% for T1a-b, 1.6-6.3% for T1c, 2.0-7.5% for T2, and 2.6-9.7% for T3 tumors with representative sensitivities of 80%, 85%, 90% and 95%, respectively. The risk may be higher when the tumor involves the upper outer quadrant of the breast, while it may be lower for an underweight woman.

CONCLUSIONS

The probability of axillary lymph node metastasis when SLNB is negative can be estimated using a Bayesian approach. Presenting the probability to the patient may guide the decision of surgery without conventional ALND.

Fluorescence navigation with indocyanine green for detecting sentinel lymph nodes in breast cancer

BACKGROUND

Sentinel lymph node biopsy using a vital dye is a convenient and safe method to assess lymph node status in breast cancer. However, intensive training is necessary to obtain a satisfactory detection rate and to avoid false-negative results. This paper presents a novel method using indocyanine green fluorescence imaging to detect sentinel lymph nodes.

METHODS

Fluorescence images were obtained using a charge coupled device camera with a cut filter as the detector, and light emitting diodes at 760 nm as the light source. When indocyanine green was injected around the areola, subcutaneous lymphatic channels draining from the areola to the axilla were visible by fluorescence within a few minutes. The sentinel lymph node was then dissected by fluorescence navigation.

RESULTS

Sentinel lymph node biopsy using the present method was performed on eighteen patients. Subcutaneous lymphatics were detectable by fluorescence in all patients, and sentinel nodes were successfully identified in 17 of 18 cases (detection rate:94%). It was possible to detect the lymphatic channels and nodes receiving indocyanine green with higher sensitivity by the fluorescence signal than by the green color.

CONCLUSION

Sentinel node biopsy guided by indocyanine green fluorescence imaging is a promising technique for further clinical exploration.

Survival analysis following sentinel lymph node biopsy: a validation trial demonstrating its accuracy in staging early breast cancer

Few long-term follow-up studies prove sentinel lymph node biopsy (SLNB) effectively stages breast cancer without the further evaluation of a completion axillary dissection. Our prospective study addressed this issue, enrolling 345 women with clinically node-negative breast cancer who underwent SLNB from October 1997 through December 2000. The median age of the patients in the study was 56.7 years. Average primary tumor size was 1.42 cm. Ninety-three patients had a positive sentinel lymph node (27%); 70 (75.3%) of these patients underwent completion axillary dissection, while 23 patients (24.7%) declined further surgery. Most (91.3%) of the patients who declined further surgery had evidence of micrometastatic disease only. The median follow-up period for all patients was 60 months. No tumor recurrences in the axilla were reported in either sentinel node-negative or -positive patients. The local and systemic recurrence rates were 3.1% and 4% in node-negative patients and 2.2% and 4.3% in node-positive patients. Two patients (0.9%) in the node-negative group and 6 (6.5%) in the node-positive group died of their disease. Estimated 5-year disease-free survival rates were 96% for node-negative patients and 87% for node-positive patients (P = 0.02). The clinical false-negative rate of the SLNB in this study was 0%. This long-term validation trial proves the accuracy of the SLNB and its extremely low false-negative rate. The findings indicate that patients with a positive SLNB have significantly different survival rates than patients with a negative SLNB.

Surgical pathological staging of breast cancer by sentinel lymph node biopsy with special emphasis on the histological work-up of axillary sentinel lymph nodes

Axillary nodal status assessed by traditional histological methods is a proven independent prognostic factor in breast cancer. Sentinel lymph node biopsy is a surgical pathologic staging procedure that not only allows the selective removal of the most likely sites of lymphogenic metastases, but also enables upstaging of breast carcinoma by detecting nodal involvement undetected by standard methods of nodal staging. This review highlights the upstaging potential of sentinel node biopsy. It also suggests that incomplete reporting of the pathological methods may make the comparisons of results from different studies difficult. The article also describes a few methods that have been claimed optimal but are probably not, and it formulates basic considerations for building up a histological protocol that can identify all metastases larger than 2 mm, which are of unquestionable prognostic relevance. These considerations are also useful for the detection of micrometastases. Issues of pathological reporting of sentinel nodal findings are also highlighted, with emphasis on the lack of standardization and on the differentiation of isolated tumor cells from micrometastases. Finally the stepwise building up of our current histology protocol and our experience gained since the introduction of sentinel node biopsy in 1997 is also briefly summarized.

Axillary recurrence after sentinel node biopsy

BACKGROUND

Sentinel node biopsy (SNB) has evolved as the standard of care in the surgical staging of breast cancer. This technique is accurate for surgical staging of axillary nodal disease. We hypothesized that axillary recurrence after SNB is rare and that SNB may provide regional control in patients with microscopic nodal involvement.

METHODS

With institutional review board approval, SNB was performed with peritumoral injection of 99mTc-labeled sulfur colloid. From 1996 to 2003, 1167 patients were entered into a prospective cancer database after surgical therapy; 916 patients consented to long-term follow-up. Fifty-two patients (5.7%) did not map successfully and were excluded, leading to a study population of 864 patients. The median follow-up was 27.4 months (range, 1-98 months).

RESULTS

The median number of sentinel nodes harvested was 2, and 633 (73%) patients had negative sentinel nodes. Thirty (4.7%) of those sentinel node-negative patients underwent completion axillary dissection, whereas 592 (94%) patients were followed up with observation. A total of 231 (27%) had positive sentinel nodes: 158 (68%) of these patients underwent completion axillary dissection, and 73 (32%) were managed with observation alone. Two (.32%) patients who were sentinel node negative had an axillary recurrence; one of these patients had undergone completion axillary dissection. No patient in the observed sentinel node-positive group had an axillary recurrence (odds ratio, .37; P = .725).

CONCLUSIONS

On the basis of a median follow-up of 27.4 months, axillary recurrence after SNB is extraordinarily rare regardless of nodal involvement, thus indicating that this technique provides an accurate measure of axillary disease and may impart regional control for patients with node-positive disease.

Meta-analysis of non-sentinel node metastases associated with micrometastatic sentinel nodes in breast cancer

BACKGROUND

The need for further axillary treatment in patients with breast cancer with low-volume sentinel node (SN) involvement (micrometastases or smaller) is controversial.

METHODS

Twenty-five studies reporting on non-SN involvement associated with low-volume SN involvement were identified using Medline and a meta-analysis was performed.

RESULTS

The weighted mean estimate for the incidence of non-SN metastases after low-volume SN involvement is around 20 per cent, whereas this incidence is around 9 per cent if the SN involvement is detected by immunohistochemistry (IHC) alone. Subset analyses suggest that studies with axillary dissection after any type of SN involvement result in somewhat higher estimates than studies allowing omission of axillary clearance, as do studies with more detailed histological evaluation of the SN compared with those with a less intensive histological protocol. Higher-quality papers yield lower pooled estimates than lower-quality papers.

CONCLUSION

The risk of non-SN metastasis with a low-volume metastasis in the SN is around 10-15 per cent, depending on the method of detection of SN involvement. This should be taken into account when assessing the risk of omission of axillary dissection after a positive SN biopsy yielding micrometastatic or immunohistochemically positive SNs.

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.