Evidence and implementation gaps in management of sentinel node-positive melanoma in the United States

Patterns of Referral for Common Cancer Surgery in the United States

BACKGROUND

Shifts in healthcare delivery have resulted in most U.S. hospitals participating in integrated health systems, many of which selectively refer complex cancer surgery to high-volume centers. However, this centralization may exacerbate barriers to access and may not be necessary for all cancer types. This study describes the prevalence and pattern of referral for surgery for common cancers and evaluate associated factors.

METHODS

The National Cancer Database was used to identify adult patients who underwent curative-intent surgical resection between 2010 and 2020 for 12 common cancers (bladder, breast, colon, kidney, lung, melanoma, oral cavity, pancreas, prostate, rectum, thyroid, and uterus). The primary outcome was receipt of referred surgical cancer care.

RESULTS

Overall, 5,406,813 patients underwent surgical resection for common cancers, with 33.7% referred for surgery after diagnosis elsewhere. Rates of referred surgery varied by disease site, ranging from 13.7% (bladder) to 58.2% (melanoma). On multivariable analysis, patients with melanoma, oral cavity, prostate, rectal, and uterine cancers (referent = breast), higher clinical stages, and increasing year of diagnosis had higher adjusted odds of referred surgical care. Nonacademic facility types, lower facility volume, higher comorbidity burden, and nonprivate insurance were associated with reduced odds of referred surgical care.

CONCLUSIONS

Likelihood of referred surgical cancer care increased over time for 11 of 12 common cancers, with the prevalence of referred care varying significantly based on disease site and sociodemographic factors. Future work evaluating associated clinical outcomes will aid in decisions regarding allocation of referral of surgical cancer care within health systems.

Recurrence Patterns for Regionally Metastatic Melanoma Treated in the Era of Adjuvant Therapy: A Systematic Review and Meta-Analysis

BACKGROUND

The purpose of this systematic review was to examine the timing and patterns of recurrence for patients with regionally metastatic melanoma on the basis of nodal management and receipt of adjuvant therapy.

METHODS

We identified randomized controlled trials and non-randomized studies published between 2010 and 2020 that reported timing and/or patterns of recurrence. We evaluated recurrence-free survival (RFS), location of recurrence, and surveillance strategy on the basis of receipt of adjuvant systemic therapy and nodal management with observation versus completion dissection. We compared differences in patterns of recurrence across studies using RevMan. RFS was evaluated graphically using point estimates and confidence intervals.

RESULTS

Among the 19 publications, there was wide variation in study populations, imaging surveillance regimens, and format of recurrence reporting. Patterns of disease recurrence did not differ between adjuvant and placebo/observation groups. A total of 11 studies reported RFS at variable time intervals, which ranged in adjuvant therapy groups (38-88% at 1 year, 29-67% at 2 years, 33-58% at 3 years, and 34-53% at 5 years) and placebo/observation groups (47-63% at 1 year, 39-47% at 2 years, 33-68% at 3 years, and 57% at 5 years). Anti-PD-1 immune therapy and BRAF/MEK inhibitor therapy were superior to placebo at year 1.

DISCUSSION

We found that adjuvant treatment improved RFS but did not alter the patterns of disease recurrence compared with patients managed without adjuvant systemic treatment. Future studies should separately report sites of disease recurrence on the basis of specific adjuvant systemic treatment and surveillance practices to better advise patients about their patterns and risk of recurrence.

Does Stage Migration Occur as a Consequence of Omitting Completion Lymph Node Dissection for Melanoma?

INTRODUCTION

Completion lymph node dissection (CLND) is no longer recommended routinely in the treatment of melanoma. CLND omission may understage patients for whom the distinction between stage IIIA and IIIB-C could alter adjuvant therapy recommendations. The aim of this study is to determine if stage migration has occurred with the declining use of CLND.

METHODS

Patients with clinically node-negative ≥ T1b cutaneous melanoma were identified from the National Cancer Database (NCDB) from 2012 to 2018. CLND utilization and changes in AJCC staging were analyzed. Patients undergoing sentinel lymph node biopsy (SLNB) alone were compared with those undergoing SLNB + CLND.

RESULTS

Overall, 68,933 patients met inclusion criteria and 60,536 underwent SLNB, of which 9031 (14.9%) were tumor positive. CLND was performed in 3776 (41.8%). Patients undergoing CLND were younger (58 versus 62 years, p < 0.0001) and more likely male (61.5% versus 57.9%, p = 0.0005). Patients were more likely to have an N classification >N1a if they received SLNB + CLND (36.8%) versus SLNB alone (19.3%), p < 0.0001. This translated to a small difference in stage IIIA patients between groups (SLNB alone 34.0%, SLNB + CLND 31.8%, p < 0.0001). Of the patients with T1b/T2a tumors who would be upstaged from IIIA to IIIC with identification of additional positive nodes, IIIC incidence was only slightly higher after SLNB + CLND compared with SLNB alone (4.4% versus 1.1%, p < 0.0001). CLND utilization dramatically decreased from 59% in 2012 to 12.6% in 2018, p < 0.0001. However, the incidence of stage IIIA disease for all patients remained stable over the 7-year study period.

CONCLUSIONS

While the utilization of CLND after positive SLNB has declined dramatically in the last 7 years, stage migration that may affect adjuvant therapy decisions has not occurred to a clinically meaningful degree.

Completion Lymph Node Dissection for Melanoma Before and After the Multicenter Selective Lymphadenectomy Trial-II in the United States

BACKGROUND

The Multicenter Selective Lymphadenectomy Trial-II (MSLT-II) revealed completion lymph node dissection (CLND) after positive sentinel lymph node biopsy (SLNB) did not improve melanoma-specific survival compared with surveillance. Given these findings and the morbidity associated with CLND, this study investigated trends in rates and predictors of CLND after MSLT-II.

METHODS

Analysis of the National Cancer Database was performed for all patients aged ≥18 years with melanoma and a positive SLNB for 2012-2019. Rates of CLND before and after publication of MSLT-II were identified and logistic regression used to identify factors associated with CLND.

RESULTS

Patients undergoing CLND declined from 55.9% pre-MSLT-II (n = 9725) to 19.5% post-MSLT-II (n = 9419) (odds ratio [OR] 0.32, 95% confidence interval [CI] 0.29-0.35). CLND was less likely in females (OR 0.83; 95% CI 0.78-0.89), older patients (vs. 18-39 yr; 40-64 yr OR 0.80, 95% CI 0.65-0.98; 65-79 yr OR 0.67, 95% CI 0.53-0.84; >80 yr OR 0.38, 95% CI 0.30-0.49), sicker patients (Deyo category ≥2 OR 0.85, 95% CI 0.73-0.99), thinner primary lesions (vs. 0.01-0.79 mm; 1.01-4.00 mm OR 1.16, 95% CI 1.01-1.33; ≥4.01 mm OR 1.31, 95% CI 1.08-1.59), patients from metro areas (Rural OR 1.31, 95% CI 1.00-1.70; Urban OR 1.15, 95% CI 1.03-1.29), and those treated at lower-volume centers (vs. lowest-volume; highest-volume OR 1.31, 95% CI 1.14-1.50; high-volume OR 1.40, 95% CI 1.24-1.57).

CONCLUSIONS

MSLT-II has impacted clinical care; however, male gender, thicker lesions, rural/urban residence, younger age, fewer comorbidities, and treatment at higher-volume centers confer a greater likelihood of undergoing CLND. Further investigations should focus on whether these populations benefit from more aggressive surgical care.

Predicting Regional Lymph Node Recurrence in the Modern Age of Tumor-Positive Sentinel Node Melanoma: The Role of the First Postoperative Ultrasound

BACKGROUND

The Multicenter Selective Lymphadenectomy Trial II (MSLT-II) led to a change in the management of tumor-positive sentinel lymph nodes (SLNs) from completion node dissection (CLND) to nodal observation. This study aimed to evaluate prognostic factors for predicting sentinel node basin recurrence (SNBR) using data from MSLT-II trial participants.

METHODS

In MSLT-II, 1076 patients were treated with observation. Patients were included in the current study if they had undergone a post-sentinel node basin ultrasound (PSNB-US) within 4 months after surgery. The study excluded patients with positive SLN by reverse transcription-polymerase chain reaction (RT-PCR) or incomplete SLN pathologic data. Primary tumor, patient, PSNB-US, and SLN characteristics were evaluated. Multivariable regression analyses were performed to determine independent prognostic factors associated with SNBR.

RESULTS

The study enrolled 737 patients: 193 (26.2%) patients with SNBR and 73 (9.9%) patients with first abnormal US. The patients with an abnormal first US were more likely to experience SNBR (23.8 vs. 5.0%). In the multivariable analyses, increased risk of SNBR was associated with male gender (adjusted hazard ratio [aHR], 1.38; 95% confidence interval [CI], 1.00-1.9; p = 0.049), increasing Breslow thickness (aHR, 1.10; 95% CI, 1.01-1.2; p = 0.038), presence of ulceration (aHR, 1.93; 95% CI, 1.42-2.6; p < 0.001), sentinel node tumor burden greater than 1 mm (aHR, 1.91; 95% CI, 1.10-3.3; p = 0.022), lymphovascular invasion (aHR, 1.53; 95% CI, 1.00-2.3; p = 0.048), and presence of abnormal PSNB-US (aHR, 4.29; 95% CI, 3.02-6.1; p < 0.001).

CONCLUSIONS

The first postoperative US together with clinical and pathologic factors may play an important role in predicting SNBR.

Real-World Adherence to Nodal Surveillance for Sentinel Lymph Node-Positive Melanoma

BACKGROUND

Patients with sentinel lymph node-positive (SLN+) melanoma are increasingly undergoing active nodal surveillance over completion lymph node dissection (CLND) since the Second Multicenter Selective Lymphadenectomy Trial (MSLT-II). Adherence to nodal surveillance in real-world practice remains unknown.

METHODS

In a retrospective cohort of SLN+ melanoma patients who underwent nodal surveillance at a single institution from July 2017 through April 2021, this study evaluated adherence to nodal surveillance ultrasound (US). Adherence to nodal US was compared with adherence to other surveillance methods based on receipt of adjuvant therapy. Early recurrence data were reported using descriptive statistics.

RESULTS

Among 109 SLN+ patients, 37 (34%) received US surveillance at recommended intervals. Of the 72 (66%) non-adherent patients, 16 were lost to follow-up, and 33 had planned follow-up at an outside institution without available records. More patients had a minimum of bi-annual clinic visits (83%) and cross-sectional imaging (53%) compared to those who were adherent with nodal US. The patients who received adjuvant therapy (60%) had fewer ultrasounds (p < 0.01) but more exams (p < 0.01) and a trend toward more cross-sectional imaging (p = 0.06). Of the overall cohort, 26 patients (24%) experienced recurrence at a median follow-up period of 15 months. Of these recurrences, 10 were limited to the SLN basin, and all of these isolated nodal recurrences were resectable.

CONCLUSIONS

Pragmatic challenges to real-world delivery of nodal surveillance remain after MSLT-II, and adjuvant therapy appears to be associated with a decreased likelihood of US adherence. Understanding US utility alongside cross-sectional imaging will be critical as increasingly more patients undergo nodal surveillance and adjuvant therapy.