Melanoma in women of childbearing age and in pregnancy in California, 1994-2015: a population-based cohort study

BACKGROUND

Melanoma is one of the most common malignancies during pregnancy. There is debate regarding the impact of pregnancy on the prognosis of melanoma. Recent large population-based studies from the United States are lacking.

OBJECTIVES

To determine the characteristics and survival of women with pregnancy-associated melanoma.

METHODS

This population-based, retrospective cohort study used California Cancer Registry data linked with state-wide hospitalization and ambulatory surgery data to identify 15-44-year-old female patients diagnosed with melanoma in 1994-2015, including pregnant patients. Multivariable logistic regression compared demographic and clinical characteristics between pregnant and non-pregnant women with melanoma. Multivariable cox proportional hazards regression models assessed melanoma-specific and overall survival.

RESULTS

We identified 13 108 patients, of which 1406 were pregnant. Pregnancy-associated melanoma was more frequent in Hispanic compared to non-Hispanic White women. Melanoma occurring post-partum was associated with greater tumour thickness (2.01-4.00 vs. 0.01-1.00 mm, odds ratio 1.75, 95% confidence interval: 1.03-2.98). There were otherwise no significant differences between pregnant and non-pregnant women. Worse survival was associated with Asian, Black and Native American race/ethnicity (vs. non-Hispanic White), lower neighbourhood socio-economic status, public insurance, tumour site, greater tumour thickness and lymph node involvement, but not pregnancy.

CONCLUSIONS

Melanoma occurring post-partum was associated with greater tumour thickness, but pregnancy status did not affect survival after melanoma. Race/ethnicity, socio-economic status and health insurance impacted survival, emphasizing the importance of reducing health disparities.

High-Plex Spatial RNA Profiling Reveals Cell Type‒Specific Biomarker Expression during Melanoma Development

Early diagnosis of melanoma is critical for improved survival. However, the biomarkers of early melanoma evolution and their origin within the tumor and its microenvironment, including the keratinocytes, are poorly defined. To address this, we used spatial transcript profiling that maintains the morphological tumor context to measure the expression of >1,000 RNAs in situ in patient-derived formalin-fixed, paraffin-embedded tissue sections in primary melanoma and melanocytic nevi. We profiled 134 regions of interest (each 200 μm in diameter) enriched in melanocytes, neighboring keratinocytes, or immune cells. This approach captured distinct expression patterns across cell types and tumor types during melanoma development. Unexpectedly, we discovered that S100A8 is expressed by keratinocytes within the tumor microenvironment during melanoma growth. Immunohistochemistry of 252 tumors showed prominent keratinocyte-derived S100A8 expression in melanoma but not in benign tumors and confirmed the same pattern for S100A8's binding partner S100A9, suggesting that injury to the epidermis may be an early and readily detectable indicator of melanoma development. Together, our results establish a framework for high-plex, spatial, and cell type‒specific resolution of gene expression in archival tissue applicable to the development of biomarkers and characterization of tumor microenvironment interactions in tumor evolution.

Pink verrucous plaque in a man with systemic mastocytosis

Porokeratosis ptychotropica is a rare and commonly misdiagnosed subtype of porokeratosis involving the body folds. We present a 53-year-old man with systemic mastocytosis who presented with a pruritic, verrucous plaque in the gluteal fold that showed multiple cornoid lamellae on histopathologic evaluation, diagnostic of porokeratosis ptychotropica. Various treatments have been reported, including topical corticosteroids, retinoids, vitamin D analogs, calcineurin inhibitors, imiquimod, phototherapy, cryotherapy, or ablative laser therapy, but recurrences are common.

Clinical pharmacokinetics of theophylline and levels of alpha 1-acid glycoprotein in smokeless tobacco users

Elimination half-life and apparent volume of distribution of theophylline were determined in ten healthy volunteers who used smokeless tobacco (snuff or chewing tobacco) regularly but did not smoke cigarettes. Serum concentrations of the acute phase reactant alpha 1-acid glycoprotein (AAG) were also measured. The elimination half-life of theophylline was 9.32 +/- 3.40 hours (mean +/- standard deviation), the apparent volume of distribution was 0.45 +/- 0.03 L/kg, and AAG concentrations were 63.8 +/- 15.76 mg/dL. All these values are comparable to values reported for nonsmokers. These results suggest that nonsmoking users of ST should be considered to be tobacco nonusers for purposes of planning theophylline dosing and monitoring strategies.