Prognostic factors for pulmonary metastasectomy in malignant melanoma: size matters

Recurrence-free survival curve for pulmonary metastasectomy in colorectal cancer plateaus at 3 years

Pulmonary metastasectomy in colorectal cancer (CRC) has encouraging results; however, specific criteria for lung resection and the timing of resection remain undetermined. Therefore, in this study, we aimed to examine the long-term prognosis and 10-year survival rates and analyze poor prognostic factors in patients who underwent resection of pulmonary metastases from CRC. This retrospective, single-institution study included 156 patients with controlled primary CRC and metastases confined to the lungs or liver who underwent pulmonary metastasectomy between 2005 and 2022. Statistical analyses were conducted using the X2 and two-tailed Student's t test to compare variables. The receiver operating characteristic (ROC) curve was used to determine the appropriate cut-off point for tumor size as a predictive factor of survival. Recurrence-free survival (RFS) and overall survival (OS) were estimated using the Kaplan-Meier method, and non-parametric group comparisons were performed using log-rank tests. The 5- and 10-year OS rates were 67% and 59%, respectively. Further, there was no recurrence 38 months post-surgery, and the RFS curve plateaued. Moreover, by 88 months post-surgery, no deaths occurred, and the OS curve plateaued. Multivariate analysis revealed that a pulmonary metastatic tumor >14 mm and disease-free interval <2 years indicated poor prognosis. The RFS curve for pulmonary metastasectomy may plateau approximately 3 years after surgery. Pulmonary metastasectomy can achieve long-term survival in selected patients with CRC. Furthermore, surgical resection of recurrence after pulmonary metastasectomy may lead to better results. Thus, tumor size and disease-free interval may be independent prognostic factors.

Pulmonary metastasectomy after immune checkpoint inhibitors in malignant melanoma

The management of malignant melanoma with pulmonary metastases is controversial and occasionally requires multimodality management, including pulmonary metastasectomy after immune checkpoint inhibitors (ICIs). However, limited data are available on these patients. We described a case series of three consecutive patients who underwent pulmonary metastasectomy after ICIs for malignant melanoma and discussed the important characteristics of these patients. After pulmonary metastasectomy, none of the patients had recurrent pulmonary metastases, although extrapulmonary metastases were developed. Our case series suggests that pulmonary metastasectomy after ICIs may control pulmonary metastases in carefully selected patients with malignant melanoma.

Long-Term Follow-Up after Laser-Assisted Pulmonary Metastasectomy Shows Complete Lung Function Recovery

Preserving maximum lung function is a fundamental goal of parenchymal-sparing pulmonary laser surgery. Long-term studies for follow-up of lung function after pulmonary laser metastasectomy are lacking. However, a sufficient postoperative lung function is essential for quality of life and reduces potential postoperative complications. In this study, we investigate the extent of loss in lung function following pulmonary laser resection after three, six, and twelve months. We conducted a retrospective analysis using a prospective database of 4595 patients, focusing on 126 patients who underwent unilateral pulmonary laser resection for lung metastases from 1996 to 2022 using a 1318 nm Nd:YAG laser or a high-power pure diode laser. Results show that from these patients, a median of three pulmonary nodules were removed, with 75% presenting central lung lesions and 25% peripheral lesions. The median preoperative FEV1 was 98% of the predicted value, decreasing to 71% postoperatively but improving to 90% after three months, 93% after six months, and 96% after twelve months. Statistical analysis using the Friedman test indicated no significant difference in FEV1 between preoperative levels and those at six and twelve months post-surgery. The findings confirm that pulmonary laser surgery effectively preserves lung function over time, with patients generally regaining their preoperative lung function within a year, regardless of the metastases' location.

Surgical Resection of Pulmonary Metastases from Melanoma in Oligometastatic Patients: Results from a Multicentric Study in the Era of Immunoncology and Targeted Therapy

In the last decade, the emergence of effective systemic therapies (ESTs) in the form of both targeted and immuno-based therapies has revolutionized the treatment of patients with advanced stage III and stage IV melanoma. Even though lungs represent the most frequent site of melanoma metastases, only limited data are available on the role of surgery in isolated pulmonary metastases from malignant melanoma (PmMM) in the era of ESTs. The aim of this study is to describe the outcomes of patients who underwent metastasectomy of PmMM in the era of ESTs, in order to identify prognostic factors affecting survival and to provide a framework for more informed patient selection of treatmeant with lung surgery in the future. Clinical data of 183 patients who underwent metastasectomy of PmMM between June 2008 and June 2021 were collected among four Italian Thoracic Centers. The main clinical, surgical and oncological variables reviewed were: sex, comorbidities, previous oncological history, melanoma histotypes and primary site, date of primary cancer surgical treatment, melanoma growth phase, Breslow thickness, mutation pattern disease, stage at diagnosis, metastatic sites, DFI (Disease Free Interval), characteristics of lung metastases (number, side, dimension, type of resection), adjuvant therapy after lung metastasectomy, site of recurrence, disease-free survival (DFS) and cancer-specific survival (CSS; defined as the time interval between the first melanoma resection or lung metastasectomy and death from cancer). All patients underwent surgical resection of the primary melanoma before lung metastasectomy. Twenty-six (14.2%) patients already had a synchronous lung metastasis at the time of primary melanoma diagnosis. A wedge resection was performed in 95.6% of cases to radically remove the pulmonary localizations, while an anatomical resection was necessary in the remaining cases. The incidence of major post-operative complications was null, while only 21 patients (11.5%) developed minor complications (mainly air leakage followed by atrial fibrillation). The mean in-hospital stay was 4.46 ± 2.8 days. Thirty- and sixty-day mortality were null. After lung surgery, 89.6% of the population underwent adjuvant treatments (47.0% immunotherapy, 42.6% targeted therapy). During a mean FUP of 107.2 ± 82.3 months, 69 (37.7%) patients died from melanoma disease, 11 (6.0%) from other causes. Seventy-three patients (39.9%) developed a recurrence of disease. Twenty-four (13.1%) patients developed extrapulmonary metastases after pulmonary metastasectomy. The CSS from melanoma resection was: 85% at 5 years, 71% at 10 years, 54% at 15 years, 42% at 20 years and 2% at 25 years. The 5- and 10-year CSS from lung metastasectomy were 71% and 26%, respectively. Prognostic factors negatively affecting CSS from lung metastasectomy at multivariable analysis were: melanoma vertical growth (p = 0.018), previous metastatic sites other than lung (p < 0.001) and DFI < 24 months (p = 0.007). Our results support the evidence that surgical indication confirms its important role in stage IV melanoma with resectable pulmonary metastases, and selected patients can still benefit from pulmonary metastasectomy in terms of overall cancer specific survival. Furthermore, the novel systemic therapies may contribute to prolonged survival after systemic recurrence following pulmonary metastasectomy. Patients with long DFI, radial growth melanoma phase and no site of metastatization other than lung seem to be the best candidate cases for lung metastasectomy; however, to drive stronger conclusions, further studies evaluating the role of metastasectomy in patients with iPmMM are needed.

Outcomes After Curative Metastasectomy for Patients with Malignant Melanoma: A Systematic Review and Meta-analysis

BACKGROUND

Evidence on the role of curative metastasectomy (CM) for malignant melanoma (MM) patients is limited, especially in the current era of effective systemic therapy. A systematic review and meta-analysis were performed to ascertain the role of CM compared with incomplete or nonsurgical treatment for patients with MM.

METHODS

Medline, Embase, and Scopus databases were searched for studies investigating CM for MM until 30 September 2021. The review included studies that compared CM with no-CM and reported a hazard ratio (HR) after multivariate analysis for overall survival. A random-effects model with inverse variance was used to calculate pooled HR. The Newcastle-Ottawa Scale was used to assess the risk of bias.

RESULTS

For the final analysis, 40 studies including 31,282 patients (CM, 9958; no-CM, 21,324) were considered. Compared with no-CM, CM was associated with a significantly lower risk of death (HR, 0.42; 95% confidence interval [CI], 0.38-0.47; p < 0.00001). Subgroup analysis showed that the outcome was independent of the effective systemic therapy and anatomic location of metastasis. An unfavorable prognosis was associated with advancing age, elevated lactate dehydrogenase (LDH), male gender, prior stage 3 disease, multiple metastases and organ sites, and shorter disease-free interval.

CONCLUSION

Curative metastasectomy for MM is associated with a lower risk of death than non-curative treatment methods. Selection bias and underlying weakness of studies reduced the strength of evidence in this review. However, CM should be a part of the multimodality treatment of MM whenever technically feasible.

The Prognostic Relevance of PMCA4 Expression in Melanoma: Gender Specificity and Implications for Immune Checkpoint Inhibition

PMCA4 is a critical regulator of Ca2+ homeostasis in mammalian cells. While its biological and prognostic relevance in several cancer types has already been demonstrated, only preclinical investigations suggested a metastasis suppressor function in melanoma. Therefore, we studied the expression pattern of PMCA4 in human skin, nevus, as well as in primary and metastatic melanoma using immunohistochemistry. Furthermore, we analyzed the prognostic power of PMCA4 mRNA levels in cutaneous melanoma both at the non-metastatic stage as well as after PD-1 blockade in advanced disease. PMCA4 localizes to the plasma membrane in a differentiation dependent manner in human skin and mucosa, while nevus cells showed no plasma membrane staining. In contrast, primary cutaneous, choroidal and conjunctival melanoma cells showed specific plasma membrane localization of PMCA4 with a wide range of intensities. Analyzing the TCGA cohort, PMCA4 mRNA levels showed a gender specific prognostic impact in stage I-III melanoma. Female patients with high transcript levels had a significantly longer progression-free survival. Melanoma cell specific PMCA4 protein expression is associated with anaplasticity in melanoma lung metastasis but had no impact on survival after lung metastasectomy. Importantly, high PMCA4 transcript levels derived from RNA-seq of cutaneous melanoma are associated with significantly longer overall survival after PD-1 blockade. In summary, we demonstrated that human melanoma cells express PMCA4 and PMCA4 transcript levels carry prognostic information in a gender specific manner.

Pulmonary metastasectomy in the era of targeted therapy and immunotherapy

Metastatic melanoma is a fatal malignancy with a high mortality and morbidity. Since the early 1970s, available medical therapies were limited in improving survival. Surgery represented the best chance for a cure. However, surgery could only be offered to selected patients. The current landscape of treatment has radically evolved since the introduction of targeted and immunotherapies including BRAF and MEK inhibitors, and checkpoint blockers, like PD-1 and CTLA-4 antibodies. These new therapies have seen survival rates matching, and in some cases surpassing, that of surgery. Anti-PD1 and CTLA-4 combination treatments are associated with severe side effects and BRAF and MEK inhibitor combinations may trigger initial tumour responses but prolonged use have resulted in the development of resistant tumour clones and disease relapse. This review examines the role of pulmonary metastasectomy for lung metastasis from malignant melanoma in the current landscape of effective targeted therapy and immunotherapy.

A Novel Nomogram and Risk Classification System Predicting the Cancer-Specific Mortality of Patients with Initially Diagnosed Metastatic Cutaneous Melanoma

BACKGROUND

Cutaneous melanoma and distant organ metastasis has varying outcomes. Considering all prognostic indicators in a prediction model might assist in selecting cases who could benefit from a personalized therapy strategy.

OBJECTIVE

This study aimed to develop and validate a prognostic model for patients with metastatic melanoma.

METHODS

A total of 1535 cases diagnosed with metastatic cutaneous melanoma (stage IV) were identified from the Surveillance, Epidemiology, and End Results database. Patients were randomly divided into the training (n = 1023) and validation (n = 512) cohorts. A prognostic nomogram was established based predominantly on results from the competing-risk regression model for predicting cancer-specific death (CSD). The area under the time-dependent receiver operating characteristic curve (AUC), calibration curves, and decision curve analyses (DCAs) were used to evaluate the nomogram.

RESULTS

No significant differences were observed in the clinical characteristics between the training and validation cohorts. In the training cohort, patient-, tumor-, and treatment-related predictors of CSD for metastatic melanoma included age, sex, race, marital status, insurance, American Joint Committee on Cancer T and N stage, number of metastatic organs, surgical treatment, and chemotherapy. All these factors were used for nomogram construction. The time-dependent AUC values of the training and validation cohorts suggested a favorable performance and discrimination of the nomogram. The 6-, 12-, and 18-month AUC values were 0.706, 0.700, and 0.706 in the training cohort, and 0.702, 0.670, and 0.656 in the validation cohort, respectively. The calibration curves for the probability of death at 6, 12, and 18 months showed acceptable agreement between the values predicted by the nomogram and the observed outcomes in both cohorts. DCA curves showed good positive net benefits in the prognostic model among most of the threshold probabilities at different time points (death at 6, 12, and 18 months). Based on the total nomogram scores of each case, all patients were divided into the low-risk (n = 511), intermediate-risk (n = 512), and high-risk (n = 512) groups, and the risk classification could identify cases with a high risk of death in both cohorts.

CONCLUSIONS

A predictive nomogram and a corresponding risk classification system for CSD in patients with metastatic melanoma were developed in this study, which may assist in patient counseling and in guiding clinical decision making for cases with metastatic melanoma.