Local recurrence and metastasis in patients with malignant melanomas after surgery: A single-center analysis of 202 patients in South Korea

The diameter of cutaneous melanoma serves as a prognostic indicator for survival among acral-melanoma predominant East Asian patients

BACKGROUND

Tumor staging plays a pivotal role in melanoma management, where the depth of tumor invasion has been traditionally used as the cornerstone of staging. Paradoxically, the tumor diameter has not been integrated into the staging system. The aim of this study is to elucidate the clinical implications and prognostic value of tumor diameter in cutaneous melanoma, with a particular emphasis on the acral-melanoma predominant East Asian population, thus potentially enriching the clinical evaluation and treatment strategies for cutaneous melanoma.

METHODS

From January 1st, 2006 to December 31st, 2022, a total of 352 patients were diagnosed with melanoma in our center. Among them, there were 135 patients diagnosed as cutaneous melanoma who received complete surgical wide excision and regional lymph nodes assessment. The diameter of the tumor, the depth of tumor invasion, lymph node status and patient survival were all collected and analyzed.

RESULTS

The diameter of cutaneous melanoma had a weak positive correlation with tumor thickness (r = 0.26), however, it still had a significant predictive value for patients' overall survival (p = 0.005) and disease free survival (p = 0.023). As for lymph node metastasis prediction, the Breslow thickness had a better predictive value than tumor diameter (p = 0.002 vs. p = 0.565).

CONCLUSIONS

In this study, though with only weak positive correlation to tumor thickness, the tumor diameter of melanoma showed a statistically significant correlation with the patients' overall survival and disease free survival. However, the larger tumor diameter cannot be used as an indicator of high risk of lymph node metastasis.

Computational modeling of locoregional recurrence with spatial structure identifies tissue-specific carcinogenic profiles

Introduction

Local and regional recurrence after surgical intervention is a significant problem in cancer management. The multistage theory of carcinogenesis precisely places the presence of histologically normal but mutated premalignant lesions surrounding the tumor - field cancerization, as a significant cause of cancer recurrence. The relationship between tissue dynamics, cancer initiation and cancer recurrence in multistage carcinogenesis is not well known.

Methods

This study constructs a computational model for cancer initiation and recurrence by combining the Moran and branching processes in which cells requires 3 or more mutations to become malignant. In addition, a spatial structure-setting is included in the model to account for positional relativity in cell turnover towards malignant transformation. The model consists of a population of normal cells with no mutation; several populations of premalignant cells with varying number of mutations and a population of malignant cells. The model computes a stage of cancer detection and surgery to eliminate malignant cells but spares premalignant cells and then estimates the time for malignant cells to re-emerge.

Results

We report the cellular conditions that give rise to different patterns of cancer initiation and the conditions favoring a shorter cancer recurrence by analyzing premalignant cell types at the time of surgery. In addition, the model is fitted to disease-free clinical data of 8,957 patients in 27 different cancer types; From this fitting, we estimate the turnover rate per month, relative fitness of premalignant cells, growth rate and death rate of cancer cells in each cancer type.

Discussion

Our study provides insights into how to identify patients who are likely to have a shorter recurrence and where to target the therapeutic intervention.

Prediction of early-stage melanoma recurrence using clinical and histopathologic features

Prognostic analysis for early-stage (stage I/II) melanomas is of paramount importance for customized surveillance and treatment plans. Since immune checkpoint inhibitors have recently been approved for stage IIB and IIC melanomas, prognostic tools to identify patients at high risk of recurrence have become even more critical. This study aims to assess the effectiveness of machine-learning algorithms in predicting melanoma recurrence using clinical and histopathologic features from Electronic Health Records (EHRs). We collected 1720 early-stage melanomas: 1172 from the Mass General Brigham healthcare system (MGB) and 548 from the Dana-Farber Cancer Institute (DFCI). We extracted 36 clinicopathologic features and used them to predict the recurrence risk with supervised machine-learning algorithms. Models were evaluated internally and externally: (1) five-fold cross-validation of the MGB cohort; (2) the MGB cohort for training and the DFCI cohort for testing independently. In the internal and external validations, respectively, we achieved a recurrence classification performance of AUC: 0.845 and 0.812, and a time-to-event prediction performance of time-dependent AUC: 0.853 and 0.820. Breslow tumor thickness and mitotic rate were identified as the most predictive features. Our results suggest that machine-learning algorithms can extract predictive signals from clinicopathologic features for early-stage melanoma recurrence prediction, which will enable the identification of patients that may benefit from adjuvant immunotherapy.

N-Acetylcysteine Promotes Metastatic Spread of Melanoma in Mice

Simple Summary

Malignant melanoma is a cancer derived from melanocytes, the cells that produce pigment (melanin) in the skin. It develops on the skin, but can also appear on the mucous membranes and in other locations. Melanomas are responsible for 80% of deaths related to skin cancers. In recent years, the number of cases has increased alarmingly, likely in relation to sun exposure habits. Once melanoma spreads to distant parts of the body, the 5-year survival rate is about 10%. N-acetylcysteine (NAC) is a drug with antioxidant properties, and thereby could play a role in preventing cancer. NAC is commonly used as a mucolytic in different respiratory diseases, to treat acetaminophen (Tylenol) poisoning, and is also present in different nutritional supplements. Nevertheless, the use of NAC and other antioxidants in cancer has been questioned. Here, we show that high therapeutic doses of NAC may cause metastatic spread of a malignant melanoma.

Abstract

N-acetylcysteine (NAC) is a direct Cys donor and a promoter of glutathione (GSH) synthesis. GSH regulates melanoma growth and NAC has been suggested to increase melanoma metastases in mice. We found that high therapeutic doses of NAC do not increase the growth of melanoma xenografts, but can cause metastatic spread and distant metastases. Nevertheless, this is not due to an antioxidant effect since NAC, in fact, increases the generation of reactive oxygen species in the growing metastatic melanoma. Trolox, an antioxidant vitamin E derivative, administered in vivo, decreased metastatic growth. Metastatic cells isolated from NAC-treated mice showed an increase in the nuclear translocation of Nrf2, as compared to controls. Nrf2, a master regulator of the antioxidant response, controls the expression of different antioxidant enzymes and of the γ-glutamylcysteine ligase (the rate-limiting step in GSH synthesis). Cystine uptake through the xCT cystine-glutamate antiporter (generating intracellular Cys) and the γ-glutamylcysteine ligase activity are key to control metastatic growth. This is associated to an increase in the utilization of L-Gln by the metastatic cells, another metastases promoter. Our results demonstrate the potential of NAC as an inducer of melanoma metastases spread, and suggest that caution should be taken when administering GSH promoters to cancer patients.

Factors influencing locoregional recurrence and distant metastasis in Asian patients with cutaneous melanoma after surgery: A retrospective analysis in a tertiary hospital in Taiwan

BACKGROUND

The goal of this study was to investigate the prognostic factors for locoregional recurrence and metastasis in patients with cutaneous melanoma (CM) who underwent surgery, especially in the acral lentiginous melanoma (ALM) subtype.

METHODS

This study was a retrospective review of patients who underwent surgery for CM at Taipei Veterans General Hospital between 2000 and 2018. We investigated the risk factors for locoregional and distant metastases. The association between clinicopathological factors and locoregional recurrence and distant metastasis of the CM and ALM subtypes was analyzed. In addition, the outcomes between the ALM and non-ALM groups were compared.

RESULTS

A total of 161 patients were included in the analysis. The most common histological subtype was ALM. The overall locoregional recurrence rate of CM was 13.0% and the distant metastasis rate was 42.9%, whereas that of the ALM subtype was 12.5% and 45.5%, respectively. In patients with CM, male sex, tumor with lymphovascular invasion, and positive lymph node status were the prognostic factors for both locoregional recurrence and distant metastasis. Among the patients with ALM, positive lymph node status was significantly associated with both locoregional recurrence and distant metastasis.

CONCLUSION

In this cohort, factors influencing locoregional recurrence and distant metastasis were similar between the ALM and non-ALM groups. The above-recommended surgical margin did not show any benefit in either the CM or the ALM subtype. ALM can be handled using the same surgical strategy as CM in the Asian population.

IL-12 inhibits postoperative residual tumor growth in murine models of sarcoma and renal carcinoma

BACKGROUND

Surgical tumor removing is the most common procedure after a confirmed cancer diagnosis with no detected metastasis. Surgery can reduce tumor burden and address pathologic changes caused by local compression of tissues by the tumor. This lowers the chances of tumor cell spreading and creates more favorable conditions for further treatment. However, not all tumor cells can be eliminated through surgery. Even in the early stages of the disease, tumor cells often metastasize and cannot be identified by current detection methods. These tiny, disseminated tumors are often the cause of tumor recurrence. There is currently a lack of effective treatment options that can completely prevent tumor recurrence after surgery.

METHODS

To simulate the actual clinical situation, we selected murine-derived tumor cell lines S180 and Kcc853 to establish a post-transplantation residual tumor model in mice. Surgery was performed on mice inoculated with tumors. Tumor tissue was partially excised to set up the postsurgical residual tumor models. The model simulated the clinical situation where tumor cells were not completely eliminated or there were small tumors that had metastasized before surgery. IL-12 was injected to observe its effect on residual tumors or metastatic microtumors.

RESULTS

The administration of IL-12 after surgery can significantly inhibit the growth of residual tumors and metastasis, improve the postoperative tumor-free rate and address the problem of tumor recurrence caused by the growth of residual tumors and micro-metastasis. Therefore, the use of IL-12 antitumor cytokine combined with surgery can effectively inhibit tumor recurrence.

CONCLUSION

Low-dose IL-12 (1-10 ng/kg in humans) can inhibit residual tumor growth.