Christian Ingvar

Completion Dissection or Observation for Sentinel-Node Metastasis in Melanoma

BACKGROUND Sentinel‐lymph‐node biopsy is associated with increased melanoma‐specific survival (i.e., survival until death from melanoma) among patients with node‐positive intermediate‐thickness melanomas (1.2 to 3.5 mm). The value of completion lymph‐node dissection for patients with sentinel‐node metastases is not clear. METHODS In an international trial, we randomly assigned patients with sentinel‐node metastases detected by means of standard pathological assessment or a multimarker molecular assay to immediate completion lymph‐node dissection (dissection group) or nodal observation with ultrasonography (observation group). The primary end point was melanoma‐specific survival. Secondary end points included disease‐free survival and the cumulative rate of nonsentinel‐node metastasis. RESULTS Immediate completion lymph‐node dissection was not associated with increased melanoma‐specific survival among 1934 patients with data that could be evaluated in an intention‐to‐treat analysis or among 1755 patients in the per‐protocol analysis. In the per‐protocol analysis, the mean (±SE) 3‐year rate of melanoma‐specific survival was similar in the dissection group and the observation group (86±1.3% and 86±1.2%, respectively; P=0.42 by the log‐rank test) at a median follow‐up of 43 months. The rate of disease‐free survival was slightly higher in the dissection group than in the observation group (68±1.7% and 63±1.7%, respectively; P=0.05 by the log‐rank test) at 3 years, based on an increased rate of disease control in the regional nodes at 3 years (92±1.0% vs. 77±1.5%; P<0.001 by the log‐rank test); these results must be interpreted with caution. Nonsentinel‐node metastases, identified in 11.5% of the patients in the dissection group, were a strong, independent prognostic factor for recurrence (hazard ratio, 1.78; P=0.005). Lymphedema was observed in 24.1% of the patients in the dissection group and in 6.3% of those in the observation group. CONCLUSIONS Immediate completion lymph‐node dissection increased the rate of regional disease control and provided prognostic information but did not increase melanoma‐specific survival among patients with melanoma and sentinel‐node metastases. (Funded by the National Cancer Institute and others; MSLT‐II ClinicalTrials.gov number, NCT00297895.)

Serial monitoring of circulating tumor DNA in patients with primary breast cancer for detection of occult metastatic disease.

Metastatic breast cancer is usually diagnosed after becoming symptomatic, at which point it is rarely curable. Cell‐free circulating tumor DNA (ctDNA) contains tumor‐specific chromosomal rearrangements that may be interrogated in blood plasma. We evaluated serial monitoring of ctDNA for earlier detection of metastasis in a retrospective study of 20 patients diagnosed with primary breast cancer and long follow‐up. Using an approach combining low‐coverage whole‐genome sequencing of primary tumors and quantification of tumor‐specific rearrangements in plasma by droplet digital PCR, we identify for the first time that ctDNA monitoring is highly accurate for postsurgical discrimination between patients with (93%) and without (100%) eventual clinically detected recurrence. ctDNA‐based detection preceded clinical detection of metastasis in 86% of patients with an average lead time of 11 months (range 0–37 months), whereas patients with long‐term disease‐free survival had undetectable ctDNA postoperatively. ctDNA quantity was predictive of poor survival. These findings establish the rationale for larger validation studies in early breast cancer to evaluate ctDNA as a monitoring tool for early metastasis detection, therapy modification, and to aid in avoidance of overtreatment.

Genome-wide meta-analysis identifies five new susceptibility loci for cutaneous malignant melanoma

Thirteen common susceptibility loci have been reproducibly associated with cutaneous malignant melanoma (CMM). We report the results of an international 2-stage meta-analysis of CMM genome-wide association studies (GWAS). This meta-analysis combines 11 GWAS (5 previously unpublished) and a further three stage 2 data sets, totaling 15,990 CMM cases and 26,409 controls. Five loci not previously associated with CMM risk reached genome-wide significance (P < 5 × 10−8), as did 2 previously reported but unreplicated loci and all 13 established loci. Newly associated SNPs fall within putative melanocyte regulatory elements, and bioinformatic and expression quantitative trait locus (eQTL) data highlight candidate genes in the associated regions, including one involved in telomere biology.

Nonsense Mutations in the Shelterin Complex Genes ACD and TERF2IP in Familial Melanoma

BACKGROUNDnThe shelterin complex protects chromosomal ends by regulating how the telomerase complex interacts with telomeres. Following the recent finding in familial melanoma of inactivating germline mutations in POT1, encoding a member of the shelterin complex, we searched for mutations in the other five components of the shelterin complex in melanoma families.nnnMETHODSnNext-generation sequencing techniques were used to screen 510 melanoma families (with unknown genetic etiology) and control cohorts for mutations in shelterin complex encoding genes: ACD, TERF2IP, TERF1, TERF2, and TINF 2. Maximum likelihood and LOD [logarithm (base 10) of odds] analyses were used. Mutation clustering was assessed with χ(2) and Fishers exact tests. P values under .05 were considered statistically significant (one-tailed with Yates correction).nnnRESULTSnSix families had mutations in ACD and four families carried TERF2IP variants, which included nonsense mutations in both genes (p.Q320X and p.R364X, respectively) and point mutations that cosegregated with melanoma. Of five distinct mutations in ACD, four clustered in the POT1 binding domain, including p.Q320X. This clustering of novel mutations in the POT1 binding domain of ACD was statistically higher (P = .005) in melanoma probands compared with population control individuals (n = 6785), as were all novel and rare variants in both ACD (P = .040) and TERF2IP (P = .022). Families carrying ACD and TERF2IP mutations were also enriched with other cancer types, suggesting that these variants also predispose to a broader spectrum of cancers than just melanoma. Novel mutations were also observed in TERF1, TERF2, and TINF2, but these were not convincingly associated with melanoma.nnnCONCLUSIONSnOur findings add to the growing support for telomere dysregulation as a key process associated with melanoma susceptibility.

Use of Phosphodiesterase Type 5 Inhibitors for Erectile Dysfunction and Risk of Malignant Melanoma.

IMPORTANCEnThe target for the oral erectile dysfunction drugs, phosphodiesterase type 5 (PDE5) inhibitors, is part of a pathway implicated in the development of malignant melanoma. An increased risk of melanoma in sildenafil users was recently reported.nnnOBJECTIVEnTo examine the association between use of PDE5 inhibitors and melanoma risk, including data on specific PDE5 inhibitors, number of prescriptions, and melanoma stage.nnnDESIGN, SETTING, AND PARTICIPANTSnNationwide, population-based, nested case-control study in the Swedish Prescribed Drug Register, the Swedish Melanoma Register, and other health care registers and demographic databases in Sweden, including 4065 melanoma cases diagnosed from 2006 through 2012 and 5 randomly selected controls per case with matching year of birth.nnnEXPOSURESnNumber of filled prescriptions for the PDE5 inhibitors sildenafil and vardenafil or tadalafil.nnnMAIN OUTCOMES AND MEASURESnRisk of melanoma; overall and by stage and risk of basal cell carcinoma in multivariable logistic regression analyses.nnnRESULTSnOf 4065 melanoma cases, 435 men (11%) had filled prescriptions for PDE5 inhibitors, as did 1713 men of 20,325 controls (8%). In multivariable analysis, there was an increased risk of melanoma in men taking PDE5 inhibitors (OR, 1.21 [95% CI, 1.08-1.36]). The most pronounced increase in risk was observed in men who had filled a single prescription (OR, 1.32 [95% CI, 1.10-1.59]; exposure rate, 4% for cases vs 3% for controls), but was not significant among men with multiple filled prescriptions (for 2-5 prescriptions: OR, 1.14 [95% CI, 0.95-1.37], 4% for cases and 3% for controls; for ≥6 prescriptions: OR, 1.17 [95% CI, 0.95-1.44], 3% for cases vs 2% for controls). PDE5 inhibitors were significantly associated with melanoma stage 0 (OR, 1.49 [95% CI, 1.22-1.83], 13% for cases vs 8% for controls) and stage I (OR, 1.21 [95% CI, 1.02-1.43], 12% for cases vs 10% for controls), but not stage II through IV (OR, 0.83 [95% CI, 0.63-1.09], 6% for cases vs 7% for controls). The risk estimates were similar for sildenafil and vardenafil or tadalafil. PDE5 inhibitor use was also associated with an increased risk of basal cell carcinoma (OR, 1.19 [95% CI, 1.14-1.25], 9% for cases vs 8% for controls). Men taking PDE5 inhibitors had a higher educational level and annual income, factors that were also significantly associated with melanoma risk.nnnCONCLUSIONS AND RELEVANCEnIn a Swedish cohort of men, the use of PDE5 inhibitors was associated with a modest but statistically significant increased risk of malignant melanoma. However, the pattern of association (eg, the lack of association with multiple filled prescriptions) raises questions about whether this association is causal.

Avoidance of sun exposure is a risk factor for all-cause mortality: results from the Melanoma in Southern Sweden cohort

Sunlight exposure and fair skin are major determinants of human vitamin D production, but they are also risk factors for cutaneous malignant melanoma (MM). There is epidemiological evidence that all‐cause mortality is related to low vitamin D levels.

Deep sequencing of uveal melanoma identifies a recurrent mutation in PLCB4.

Next generation sequencing of uveal melanoma (UM) samples has identified a number of recurrent oncogenic or loss-of-function mutations in key driver genes including: GNAQ, GNA11, EIF1AX, SF3B1 and BAP1. To search for additional driver mutations in this tumor type we carried out whole-genome or whole-exome sequencing of 28 tumors or primary cell lines. These samples have a low mutation burden, with a mean of 10.6 protein changing mutations per sample (range 0 to 53). As expected for these sun-shielded melanomas the mutation spectrum was not consistent with an ultraviolet radiation signature, instead, a BRCA mutation signature predominated. In addition to mutations in the known UM driver genes, we found a recurrent mutation in PLCB4 (c.G1888T, p.D630Y, NM_000933), which was validated using Sanger sequencing. The identical mutation was also found in published UM sequence data (1 of 56 tumors), supporting its role as a novel driver mutation in UM. PLCB4 p.D630Y mutations are mutually exclusive with mutations in GNA11 and GNAQ, consistent with PLCB4 being the canonical downstream target of the former gene products. Taken together these data suggest that the PLCB4 hotspot mutation is similarly a gain-of-function mutation leading to activation of the same signaling pathway, promoting UM tumorigenesis.

Avoidance of sun exposure as a risk factor for major causes of death: a competing risk analysis of the Melanoma in Southern Sweden cohort

Women with active sunlight exposure habits experience a lower mortality rate than women who avoid sun exposure; however, they are at an increased risk of skin cancer. We aimed to explore the differences in main causes of death according to sun exposure.

Caffeine and caffeic acid inhibit growth and modify estrogen receptor (ER) and insulin-like growth factor I receptor (IGF-IR) levels in human breast cancer

Purpose: Epidemiologic studies indicate that dietary factors, such as coffee, may influence breast cancer and modulate hormone receptor status. The purpose of this translational study was to investigate how coffee may affect breast cancer growth in relation to estrogen receptor-α (ER) status. Experimental Design: The influence of coffee consumption on patient and tumor characteristics and disease-free survival was assessed in a population-based cohort of 1,090 patients with invasive primary breast cancer in Sweden. Cellular and molecular effects by the coffee constituents caffeine and caffeic acid were evaluated in ER+ (MCF-7) and ER− (MDA-MB-231) breast cancer cells. Results: Moderate (2–4 cups/day) to high (≥5 cups/day) coffee intake was associated with smaller invasive primary tumors (Ptrend = 0.013) and lower proportion of ER+ tumors (Ptrend = 0.018), compared with patients with low consumption (≤1 cup/day). Moderate to high consumption was associated with lower risk for breast cancer events in tamoxifen-treated patients with ER+ tumors (adjusted HR, 0.51; 95% confidence interval, 0.26–0.97). Caffeine and caffeic acid suppressed the growth of ER+ (P ≤ 0.01) and ER− (P ≤ 0.03) cells. Caffeine significantly reduced ER and cyclin D1 abundance in ER+ cells. Caffeine also reduced the insulin-like growth factor-I receptor (IGFIR) and pAkt levels in both ER+ and ER− cells. Together, these effects resulted in impaired cell-cycle progression and enhanced cell death. Conclusions: The clinical and experimental findings demonstrate various anticancer properties of caffeine and caffeic acid against both ER+ and ER− breast cancer that may sensitize tumor cells to tamoxifen and reduce breast cancer growth. Clin Cancer Res; 21(8); 1877–87. ©2015 AACR.

Multiregion whole-exome sequencing uncovers the genetic evolution and mutational heterogeneity of early-stage metastatic melanoma

Cancer genome sequencing has shed light on the underlying genetic aberrations that drive tumorigenesis. However, current sequencing-based strategies, which focus on a single tumor biopsy, fail to take into account intratumoral heterogeneity. To address this challenge and elucidate the evolutionary history of melanoma, we performed whole-exome and transcriptome sequencing of 41 multiple melanoma biopsies from eight individual tumors. This approach revealed heterogeneous somatic mutations in the range of 3%-38% in individual tumors. Known mutations in melanoma drivers BRAF and NRAS were always ubiquitous events. Using RNA sequencing, we found that the majority of mutations were not expressed or were expressed at very low levels, and preferential expression of a particular mutated allele did not occur frequently. In addition, we found that the proportion of ultraviolet B (UVB) radiation-induced C>T transitions differed significantly (P < 0.001) between early and late mutation acquisition, suggesting that different mutational processes operate during the evolution of metastatic melanoma. Finally, clinical history reports revealed that patients harboring a high degree of mutational heterogeneity were associated with more aggressive disease progression. In conclusion, our multiregion tumor-sequencing approach highlights the genetic evolution and non-UVB mutational signatures associated with melanoma development and progression, and may provide a more comprehensive perspective of patient outcome. Cancer Res; 76(16); 4765-74. ©2016 AACR.