A Left-Sided Prevalence of Lentigo Maligna: A UK Based Observational Study and Review of the Evidence

Abstract

Skin cancer has been shown to present asymmetrically, prevalent on the left side of the body, more so in subtypes of cutaneous melanoma such as lentigo maligna. Biases have been linked to cumulative UV light exposure and automobile driving patterns. Though left-right ratios have previously correlated with the side men or women tend to position themselves or countries drive on, more recent trends indicate a consistent left-sided bias. To clarify reasons for changing trends, a review of the evidence base and LM's laterality in a UK cohort (99 cases 2000–2011) was conducted for the first time. The strong correlation of left-sided excess, found in both genders (ratios 1.381–1.5, P < 0.05 X 2 0.841), is congruent with more recent findings. Though evidence indicates that driving position is no longer a risk factor for LM, due most likely to improved car window UV protection, it remains the most commonly attributed cause. Understanding phenomena such as UV lights “scatter effect” or that cumulative exposure may not be a significant risk factor helps rationalize older conclusions that would otherwise appear contradictory. The reasons for left-sided excess remain unclear but may be due to factors requiring further research such as the body's anatomical/embryological asymmetry.

Melanoma: clinical, evolutive and histopathological characteristics of a series of 136 cases

“…Lentigo maligna melanoma is the histological subtype more frequently related to sun exposure. 8 , 9 The LM group presented with only one case in non-photoexposed area. Considering the patient’s age and the slow growth of the tumor, besides the difficulty regarding complete excision of these tumors, conservative treatments for LM cases can be indicated.…”

Left‐sided excess in the laterality of cutaneous melanocytic nevi and melanomas

“…However, this would only affect the face and neck, and at best the driver’s arm as well. Moreover, a left‐sided excess of melanomas was also observed in countries with left‐hand traffic [6, 11]. Intriguingly, the most pronounced left‐excess was described for Scotland, a country with left‐hand driving.…”

Linksüberhang in der Verteilung von melanozytären Nävi und Melanomen

“…Dies würde jedoch nur das Gesicht und den Hals betreffen, allenfalls noch den Arm des Fahrers. Darüber hinaus wurde in Ländern mit Linksverkehr auch ein Linksüberhang an Melanomen beobachtet [6,11]. Interessanterweise wurde der ausgeprägteste Linksüberhang sogar für Schottland beschrieben, ein Land mit Linksverkehr.…”

“…Eine asymmetrische Verteilung von Melanomen und anderen Hauttumoren zugunsten der linken Körperhälfte wurde sowohl in Ländern auf der Nord-als auch auf der Südhalbkugel wiederholt beschrieben [3,[6][7][8][9][10][11]. In unserer Studie wurde erstmals in einer deutschen Kohorte ein entsprechender Linksüberhang für kutane Melanome nachgewiesen.…”