The Association between Preoperative Vitamin D Levels and Postoperative Complications in Patients Undergoing Colorectal Liver Metastasis Surgery

(1) Background: Over the past several years, there has been a renewed interest with regard to the effect of pre-operative vitamin D levels on post-surgical outcomes. Pre-operative vitamin D deficiency has been associated with many negative post-operative outcomes. However, the role of vitamin D in postoperative outcomes in colorectal liver metastasis (CRLM) resection is relatively uninvestigated. Our study investigated the correlation between preoperative vitamin D levels and postoperative complications in patients undergoing resection for CRLM. (2) Methods: We retrospectively examined the post-operative course of 109 patients, who were evaluated based upon preoperative vitamin D levels: the first group had vitamin D levels less than 25 nmol/L (VIT D < 25 nmol/L) (n = 12) vs. the second group who had vitamin D levels equal to or greater than 25 nmol/L (VIT D ≥ 25 nmol/L) (n = 97). (3) Results: Patients with lower pre-operative vitamin D levels (VIT D < 25 nmol/L) had significantly higher rates of blood transfusions (33.3% vs. 10.3%, p = 0.01), post-operative surgical complications (50% vs. 17.5%, p = 0.009), and infectious complications (25% vs. 7.2%, p = 0.04). However, there was no difference in overall survival seen between the two groups. (4) Conclusions: The results of our study indicate that patients with preoperative vitamin D deficiency (defined as preoperative vitamin D levels less than 25 nmol/L) may have an increased risk of postoperative complications in patients undergoing liver surgery for metastatic colorectal cancer.

The Effects of Primary Tumor Location on Survival after Liver Resection for Colorectal Liver Metastasis in the Mediterranean Population

(1) Background: There is an abundance of literature available on predictors of survival for patients with colorectal liver metastases (CRLM) but minimal information available on the relationship between the primary tumor location and CRLM survival. The studies that focus on the primary tumor location and CRLM survival exhibit a great deal of controversy and inconsistency with regard to their results (some studies show statistically significant connections between the primary tumor location and prognosis versus other studies that find no significant relationship between these two factors). Furthermore, the majority of these studies have been conducted in the West and have studied more diverse and heterogenous populations, which may be a contributing factor to the conflicting results. (2) Methods: We included patients who underwent liver resection for CRLM between December 2004 and January 2019 at two university-affiliated medical centers in Israel: Carmel Medical Center (Haifa) and Rabin Medical Center (Petach Tikvah). Primary tumors located from the cecum up to and including the splenic flexure were labeled as right-sided primary tumors, whereas tumors located from the splenic flexure down to the anal verge were labeled as left-sided primary tumors. (3) Results: We identified a total of 501 patients. Of these patients, 225 had right-sided primary tumors and 276 had left-sided primary tumors. Patients with right-sided tumors were significantly older at the time of liver surgery compared to those with left-sided tumors (66.1 + 12.7 vs. 62 + 13.1, p = 0.002). Patients with left-sided tumors had slightly better overall survival rates than those with right-sided tumors. However, the differences were not statistically significant (57 vs. 50 months, p = 0.37 after liver surgery). (4) Conclusions: The primary tumor location does not significantly affect patient survival after liver resection for colorectal liver metastasis in the Mediterranean population.

Short- and Long-Term Outcomes in Elderly Patients Following Hand-Assisted Laparoscopic Surgery for Colorectal Liver Metastasis

(1) Background: Hand-assisted laparoscopic surgery (HALS) has engendered growing attention as a safe procedure for the resection of metastatic liver disease. However, there is little data available regarding the outcomes of HALS for colorectal liver metastasis (CRLM) in patients over the age of 75. (2) Methods: We compare the short- and long-term outcomes of patients >75-years-old (defined in our study as "elderly patients" and referred to as group 1, G1), with patients <75-years-old (defined in our study as "younger patients" and referred to as group 2, G2). (3) Results: Of 145 patients, 28 were in G1 and 117 were in G2. The most common site of the primary tumor was the right colon in G1, and the left colon in G2 (p = 0.05). More patients in G1 underwent laparoscopic anterior segment resection compared with G2 (43% vs. 39% respectively) (p = 0.003). 53% of patients in G1 and 74% of patients in G2 completed neoadjuvant therapy (p = 0.04). The median size of the largest metastasis was 32 (IQR 19-52) mm in G1 and 20 (IQR 13-35) mm in G2 (p = 0.001). The rate of complications (Dindo-Clavien grade ≥ III) was slightly higher in G1 (p = 0.06). The overall 5-year survival was 30% in G1 and 52% in G2 (p = 0.12). (4) Conclusions: Hand-assisted laparoscopic surgery for colorectal liver metastasis is safe and effective in an elderly patient population.

Autoimmune genetic risk variants as germline biomarkers of response to melanoma immune-checkpoint inhibition

Immune-checkpoint inhibition (ICI) treatments improve outcomes for metastatic melanoma; however, > 60% of treated patients do not respond to ICI. Current biomarkers do not reliably explain ICI resistance. Given the link between ICI and autoimmunity, we investigated if genetic susceptibility to autoimmunity modulates ICI efficacy. In 436 patients with metastatic melanoma receiving single line ICI or combination treatment, we tested 25 SNPs, associated with > 2 autoimmune diseases in recent genome-wide association studies, for modulation of ICI efficacy. We found that rs17388568-a risk variant for allergy, colitis and type 1 diabetes-was associated with increased anti-PD-1 response, with significance surpassing multiple testing adjustments (OR 0.26; 95% CI 0.12-0.53; p = 0.0002). This variant maps to a locus of established immune-related genes: IL2 and IL21. Our study provides first evidence that autoimmune genetic susceptibility may modulate ICI efficacy, suggesting that systematic testing of autoimmune risk loci could reveal personalized biomarkers of ICI response.

Novel germline risk loci in familial melanoma (FM)

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Background: While about 10% of cutaneous melanoma (CM) clusters in families, known high-risk loci explain not more than 40% of expected inherited risk. Besides the most frequently mutated genes in FM (e.g. CDKN2A), it is estimated that the remaining 60% of FM susceptibility is due to the interaction of environment with specific pools of rare known loci and yet unknown high-risk genes. In our study, we report the discoveries of novel germline genetic risk factors in FM in a recently developed FM cohort at New York University Langone Medical Center (NYULMC) consisting of CM and multiple primary melanomas (MPM) of Ashkenazi Jewish (AJ) and non-AJ European ancestries. Methods: As part of an ongoing ascertainment of FM at NYULMC, we assessed the status of CDKN2A mutations using Sanger sequencing, examining the coding regions of 47 AJ FM families and 81 non-AJ FM kindreds. In high-risk mutation-negative families, we applied whole-exome sequencing (WXS) and an innovative hot-spot mutational analysis of non-coding regions to identify novel high-risk loci associated with FM susceptibility. Results: We found that frequencies of CDKN2A deleterious mutations in our FM cohort (13%) are comparable with observations from previous studies. We have also identified a specific CDKN2A coding mutation in FM kindreds of AJ ancestry, which is particularly interesting as CDKN2A mutations in AJ cohorts have been sparsely reported in prior studies. The WXS/targeted non-coding sequencing of mutation-negative families identified putatively deleterious mutations in regulatory regions in the vicinity of several novel loci, including SMAD4 and PAX8, co-segregating in FM kindreds. Conclusions: Our unique FM ascertainment, including > 50% AJ kindreds, provides an excellent platform for mapping high-risk genetic susceptibility in FM. Novel deleterious mutations identified in non-coding regulatory regions of SMAD4 and PAX8 genes, some with increased frequency in AJ families, suggest a need for a more thorough investigation of the non-coding genome using a founder FM population, as we propose here. As our ongoing ascertainment expands, we are pursuing validation of our observations through comprehensive sequencing efforts.

Mutation burden as a potential prognostic marker of melanoma progression and survival

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Background: Recently, tumor mutation burden (TMB) has been shown to increase the presentation of neoantigens that stimulate immune tumor recognition, resulting in improved immunotherapy (IT) outcomes in melanoma and other cancers. As melanoma is highly immunogenic, here we tested whether TMB associates with immune recognition during tumor progression, hence impacting melanoma overall survival (OS), independently of IT treatment. Methods: We have generated somatic mutation data from 314 IT-naive metastatic melanomas from The Cancer Genome Atlas (TCGA). In the TCGA cohort, TMB has been calculated for 210 genes (200GS) previously established from TMB studies of anti-CTLA4 and anti-PD1/PD-L1 IT. For validation, we have sequenced exonic regions of 20 genes (20GS) with the highest TMB among 200GS in 89 IT-naive metastatic melanomas ascertained at New York University Langone Medical Center. The TMB was defined using total number of somatic, non-synonymous mutations in either 200GS (TCGA discovery) or 20GS (validation), respectively. For discovery and validation cohorts, OS from primary diagnosis of samples with high TMB was compared against low TMB, using thresholds established in previous studies. Results: We found that total TMB predicts better OS (p = 0.03, HR = 2.64) in TCGA melanomas. Restricting the analysis only to the established 200GS, this association became more significant in all patients (p = 0.01, HR = 2.67) as well as in patients without IT (p = 0.01, HR = 2.67). In the validation stage of 89 melanomas without prior IT treatment, a high TMB in a subset of 20GS accurately determined favorable OS (p = 0.02, HR = 2.69) and confirmed TCGA observations from the 200GS. Conclusions: Here we show, for the first time, that in addition to IT, high TMB predicts more favorable OS in patients that never received IT, potentially serving as a novel marker of prognosis of melanoma and likely other immunogenic tumors at early stages. In addition, our study suggests that TMB test can be robust when applied to only a small subset of genes that trigger significantly higher immunogenicity. This may also eventually assist with accurate sub-selection of early stage patients likely to respond to IT regimens.

Expression quantitative trait loci (eQTLs) as germline determinants of melanoma immunotherapy response

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Background: Approximately 40-60% of metastatic cutaneous melanoma (CM) patients do not respond to the current immunotherapy (IT) regimens, pointing to other yet unknown factors conferring IT resistance. Based on our recent findings showing that germline expression quantitative trait loci (eQTLs) in immune pathways associate with overall CM survival, in this study we tested whether germline immune-specific eQTLs also impact IT outcomes in CM. Methods: By interrogating a healthy twin cohort expression dataset (MuTHER), we have identified 50 eQTLs most significantly associated with the expression of 265 immune genes. Using the MassARRAY system, these 50 SNPs were genotyped in 138 anti-CTLA-4 treated patients, 59 PD-1 treated patients and 38 patients from combined (COMBO) treatments collected from multi-institutional collaborations. To test the association of SNPs with IT response, logistic regression was performed for each treatment group adjusting by demographic and clinical covariates. Results: We found significant associations with COMBO IT resistance for rs6673928 (OR = 4.249, p = 0.0167), an eQTL in IL10/IL19 which we have recently identified for association with melanoma survival; interestingly, it is a previously established locus associated with the risk of several autoimmune diseases. Additionally, we also identified eQTLs that are associated with IT sensitivity: rs4848306 in IL1-β with resistance to anti-CTLA-4 (OR = 0.373, p = 0.000733) and rs2071304 in SPI1with resistance to anti-PD-1 (OR = 0.3328, p = 0.0271). Conclusions: In this study we report that rs6673928, an eQTL from the IL19/IL10 locus previously shown to predict autoimmunity risk and CM survival, is also a surrogate marker of response to COMBO IT. The associations of rs6673928 with both IT response and CM survival indicate a strong relationship between interleukin pathways and the level of tumor immunogenicity. In addition to its apparent function in immune response, the putative multi-faceted role of this locus in predicting better survival and IT outcomes indicates high potential as a novel clinical target. Additional genetic and functional validation of these findings is currently underway in a large collaborative setting.

The Expression Quantitative Trait Loci in Immune Pathways and their Effect on Cutaneous Melanoma Prognosis

PURPOSE

The identification of personalized germline markers with biologic relevance for the prediction of cutaneous melanoma prognosis is highly demanded but to date, it has been largely unsuccessful. As melanoma progression is controlled by host immunity, here we present a novel approach interrogating immunoregulatory pathways using the genome-wide maps of expression quantitative trait loci (eQTL) to reveal biologically relevant germline variants modulating cutaneous melanoma outcomes.

EXPERIMENTAL DESIGN

Using whole genome eQTL data from a healthy population, we identified 385 variants significantly impacting the expression of 268 immune-relevant genes. The 40 most significant eQTLs were tested in a prospective cohort of 1,221 patients with cutaneous melanoma for their association with overall (OS) and recurrence-free survival using Cox regression models.

RESULTS

We identified highly significant associations with better melanoma OS for rs6673928, impacting IL19 expression (HR, 0.56; 95% CI, 0.41-0.77; P = 0.0002) and rs6695772, controlling the expression of BATF3 (HR, 1.64; 95% CI, 1.19-2.24; P = 0.0019). Both associations map in the previously suspected melanoma prognostic locus at 1q32. Furthermore, we show that their combined effect on melanoma OS is substantially enhanced reaching the level of clinical applicability (HR, 1.92; 95% CI, 1.43-2.60; P = 2.38e-5).

CONCLUSIONS

Our unique approach of interrogating lymphocyte-specific eQTLs reveals novel and biologically relevant immunomodulatory eQTL predictors of cutaneous melanoma prognosis that are independent of current histopathologic markers. The significantly enhanced combined effect of identified eQTLs suggests the personalized utilization of both SNPs in a clinical setting, strongly indicating the promise of the proposed design for the discovery of prognostic or risk germline markers in other cancers. Clin Cancer Res; 22(13); 3268-80. ©2016 AACR.