Population-based assessment of sentinel lymph node biopsy in the management of cutaneous melanoma.

BACKGROUND: Sentinel lymph node biopsy (SLNB) for melanoma plays a central role in determining prognosis and guiding treatment and surveillance strategies. Despite widely published guidelines for SLNB, variation exists in its use. We aimed to determine the frequency of and predictive factors for SLNB in patients with clinically node-negative melanoma in British Columbia. METHODS: A retrospective review was performed of patients with clinically node-negative melanoma diagnosed between January 2015 and December 2017. Patients included had a Breslow depth greater than 0.75 mm or a Breslow depth less than or equal to 0.75 mm with ulceration, or a mitotic rate greater than or equal to 1/mm2. SLNB was considered to be indicated for clinical stages IB to IIC (American Joint Committee on Cancer's AJCC Cancer Staging Manual, seventh edition). RESULTS: A total of 759 patients were included. SLNB was performed in 54.8% (363/662) of patients when indicated. SLNB was more likely to be performed for tumours with a Breslow depth greater than 1.0 mm or a mitotic rate greater than or equal to 1/mm2. SLNB was less likely to be performed in patients older than 75 years and with a nonextremity tumour location. Compliance with SLNB guidelines decreased distant recurrence but did not significantly affect regional recurrence, nor did it have a significant impact on overall survival among patients aged 75 years and younger. CONCLUSION: SLNB is being underutilized in British Columbia. These results are concerning and highly relevant given the rapidly evolving field of adjuvant systemic therapy for high-risk patients and the increased proportion of patients who should be considered for SLNB on the basis of the eighth edition of the AJCC Cancer Staging Manual and current guidelines. Efforts should be made to increase the use of SLNB in appropriate patients.

Staging in thick cutaneous malignant melanoma: A sequenced approach.

BACKGROUND: Patients with thick cutaneous pT4 malignant melanoma are at high risk for metastatic disease, and optimal staging is poorly defined. This study examines the frequency and modality of pre-operative staging to provoke thought on optimal staging. METHODS: A retrospective study was performed of patients with clinical T4N0 melanoma diagnosed between 2015-2017. The modality (sentinel lymph node biopsy and/or imaging), timing, and findings of staging investigations were assessed. RESULTS: One hundred thirty-six patients with pT4a or pT4b cutaneous melanoma and clinically negative regional lymph nodes were included. Forty patients underwent no staging. Thirty-six patients underwent pre-operative imaging, and of these, regional or distant disease was identified in seven patients (19%). Another 36 patients underwent upfront sentinel lymph node biopsy concurrently with wide local excision. A positive sentinel lymph node biopsy was found in eight (22%) of these patients, of which two had regional or distant metastatic disease on postoperative imaging. Of 16 who underwent a sentinel lymph node biopsy after negative pre-operative imaging, three had a positive sentinel lymph node biopsy. CONCLUSION: Staging is non-standardized and underutilized in patients with thick melanoma. With evolving systemic treatment options, a well-defined approach to staging, with consideration for pre-operative imaging in pT4 patients, is essential for high-risk patients.

Laparoscopic versus open resection in patients with locally advanced colon cancer.

BACKGROUND: Surgical resection of locally advanced colon cancer (LACC) is challenging due to tumor size and the frequent need for multivisceral resection. The role of laparoscopic resection in LACC is controversial. This study aims to compare outcomes for laparoscopic versus open surgery in LACC. METHODS: A population-based retrospective review was conducted of patients treated at a Provincial Cancer Center for LACC from 2005 to 2015. Patients with non-metastatic T4 colon cancers were included. Descriptive, survival, and recurrence analyses were used. RESULTS: In all, 1,328 patients were reviewed, 23% of whom had laparoscopic surgery. A greater number of T4b tumors were removed via an open approach (35.9% vs 12.7%, P < .001). Positive resection margins occurred in 7.5% of laparoscopic and 16.5% of open cases (P < .001), and multivisceral resection was required in 11.0% and 27.7% (P < .001), respectively. Median follow-up was 37 months (interquartile range [IQR] 17-64) during which 48.6% patients died and 42.1% developed recurrence: locoregional (15.0%), distant (35.3%), peritoneal (11.4%). Age, right-sided tumors, nodal status, and laparoscopic approach were independent predictors of peritoneal recurrence. Overall survival (OS) (73 vs 61 months, P = .188) and recurrence-free survival (RFS) (39 vs 31 months, P = .288) were similar with both approaches. Age, nodal, and margin status were predictive of OS and RFS. CONCLUSION: Open surgical approach is used more frequently when tumors invade adjacent organs or require multivisceral resections. When employed, laparoscopic approach had similar rates of survival and recurrence compared with open approach, but was an independent predictor of peritoneal recurrence. Careful patient selection in operative approach is suggested.