An objective measure of growth rate using partial biopsy specimens of melanomas that were initially misdiagnosed

Association between surgical delay and outcomes among patients with invasive cutaneous melanoma

BACKGROUND

The relationship between surgical delay and outcomes for patients with cutaneous melanoma is understudied. The objectives of this study were to determine the impact of surgical delay on regional nodal involvement and mortality in patients with cutaneous melanoma.

METHODS

Retrospective study of patients diagnosed with clinically node-negative invasive cutaneous melanoma from 2004 to 2018. Outcomes included regional lymph node disease and overall survival. Multivariable logistic regression and Cox proportional-hazards models were constructed to adjust for pertinent clinical factors.

RESULTS

Of 423,001 patients, 21.8% experienced a surgical delay (≥45 days). These patients were more likely to have nodal involvement (OR1.09; P ​= ​0.01). Surgical delay (HR1.14; P ​< ​0.001), Black race (HR1.34; P ​= ​0.002), and Medicaid (HR1.92; P ​< ​0.001) were associated with lower survival. Patients treated at academic/research (HR0.87; P ​< ​0.001) or integrated network cancer programs (HR0.89; P ​= ​0.001) had improve survival.

CONCLUSIONS

Surgical delay was frequent and resulted in higher rates of lymph node involvement and decreased overall survival.

[Translated article] Tumor Doubling Time in Skin Cancer: Can It Be Estimated and Is It Useful?

Skin cancer, like other cancers, is characterized by the uncontrolled growth of transformed cells. Tumor growth has been studied for decades. We review different methods for measuring skin tumor growth and propose a new system for estimating tumor doubling time that could be useful in the management of skin cancer.

Tumor Doubling Time in Skin Cancer: Can It Be Estimated and Is it Useful?

Skin cancer, like other cancers, is characterized by the uncontrolled growth of transformed cells. Tumor growth has been studied for decades. We review different methods for measuring skin tumor growth and propose a new system for estimating tumor doubling time that could be useful in the management of skin cancer.

Association of surgical interval and survival among hospital and non-hospital based patients with melanoma in North Carolina

Surgical excision is important for melanoma treatment. Delays in surgical excision after diagnosis of melanoma have been linked to decreased survival in hospital-based cohorts. This study was aimed at quantifying the association between the timeliness of surgical excision and overall survival in patients diagnosed with melanoma in hospital- and non-hospital-based settings, using a retrospective cohort study of patients with stage 0–III melanoma and using data linked between the North Carolina Central Cancer Registry to Medicare, Medicaid, and private health insurance plan claims across the state. We identified 6,496 patients diagnosed between 2004 and 2012 with follow-up through 2017. We categorized the time from diagnostic biopsy to surgical excision as < 6 weeks after diagnosis, 6 weeks to 90 days after diagnosis, and > 90 days after melanoma diagnosis. Multivariable Cox regression was used to estimate differences in survival probabilities. Five-year overall survival was lower for those with time to surgery over 90 days (78.6%) compared with those with less than 6 weeks (86%). This difference appeared greater for patients with Stage 1 melanoma. This study was retrospective, included one state, and could not assess melanoma specific mortality. Surgical timeliness may have an effect on overall survival in patients with melanoma. Timely surgery should be encouraged.

Measuring the horizontal and vertical growth rates of superficial spreading melanoma: a pilot study with sequential digital dermoscopy

BACKGROUND

Some authors have hypothesized that the initial kinetics of the primary melanoma (MM) growth could reflect its biologic aggressiveness. The aim of this study was to pilot a measure of the horizontal vs. vertical growth of superficial spreading melanomas (SSM).

METHODS

The dermoscopic images of twenty-three consecutive MMs (17 SSMs and 6 MMs in situ), excised after digital sequential dermoscopy, were reviewed. We built up two indexes: 1) dROG (digital Rate of Growth) defined as Breslow thickness/(t1-tR), where t1 was the reported time of the first dermoscopic image acquisition and tR was the reported time of the acquisition before the lesion excision; 2) lHGR (linear Horizontal Growth Rate) took into account the greater axis of the lesion at two time points, at the time (t1) of the first image acquisition (D1) and before (tR) lesion excision (DR). The index was computed as (DR-D1)/(t1-tR). We built up the Composite Rate of Growth index (cROG) calculated as dROG/lHRG. If the value of cROG is <1 the superficial growth is prevalent on the vertical growth, and if the value is >1 the vertical growth is prevalent on the superficial growth.

RESULTS

In 82.6% of lesions the horizontal growth was prevalent on the vertical growth, and in 17.4% of cases the vertical growth was equal or prevalent on the superficial growth.

CONCLUSIONS

A small proportion of SSMs with a slow horizontal growth could have a precocious vertical growth. Other larger studies are needed to confirm this observation.

Sequential digital dermatoscopic imaging of patients with multiple atypical nevi

Patients with multiple atypical nevi are at higher risk of developing melanoma. Among different techniques, sequential digital dermatoscopic imaging (SDDI) is a state-of-the art method to enhance diagnostic accuracy in evaluating pigmented skin lesions. It relies on analyzing digital dermatoscopic images of a lesion over time to find specific dynamic criteria inferring biologic behavior. SDDI can reduce the number of necessary excisions and finds melanomas in an early—and potentially curable—stage, but precautions in selecting patients and lesions have to be met to reach those goals.

Impact of primary care provider density on detection and diagnosis of cutaneous melanoma

INTRODUCTION

Early diagnosis of cutaneous melanoma is critical in preventing melanoma-associated deaths, but the role of primary care providers (PCPs) in diagnosing melanoma is underexplored. We aimed to explore the association of PCP density with melanoma incidence and mortality.

METHODS

All cases of cutaneous melanoma diagnosed in the United States from 2008-2012 and reported in the Surveillance, Epidemiology, and End Results (SEER) database were analyzed in 2016. County-level primary care physician density was obtained from the Area Health Resources File (AHRF). We conducted multivariate linear regression using 1) average annual melanoma incidence or 2) average annual melanoma mortality by county as primary outcomes, adjusting for demographic confounders and dermatologist density. Cox proportional hazard regression was conducted using individual outcome data from SEER with the same covariates.

RESULTS

Across 611 counties, 167,305 cases of melanoma were analyzed. Per 100,000 people, an additional 10 PCPs per county was associated with 1.62 additional cases of melanoma per year (95% CI 1.06-2.18, p<0.001). This increased incidence occurred disproportionally in early-stage melanoma (Stage 0: 0.69 cases (0.38-1.00), p<0.001; Stage I: 0.63 cases (0.37-0.89), p<0.001; Stage II: 0.11 cases (0.03-0.19), p = 0.005). There was no statistically significant association between PCP density and incidence of stage III or IV melanoma, or with melanoma-specific mortality. Survival analysis demonstrated elimination of 5-year post-diagnosis mortality risk in medically underserved counties after adjusting for stage.

CONCLUSIONS

Higher densities of PCPs may be linked to increased diagnosis of early-stage melanoma without corresponding decreases in late-stage diagnoses or melanoma-associated mortality.

Melanomas vs. nevi in high-risk patients under long-term monitoring with digital dermatoscopy: do melanomas and nevi already differ at baseline?

BACKGROUND

What lesions to select for a most efficient dermatoscopic monitoring of patients with multiple nevi remains an unresolved issue.

OBJECTIVE

To compare the grade of atypia of melanomas and nevi of the same patient at baseline.

METHODS

Prospective observational study using 236 dermatoscopic baseline images (59 quartets from 59 patients, each including one melanoma detected during follow-up and three nevi). Dermatologists (n = 26) were asked to assess the 'grade of dermatoscopic atypia' on a numerical scale and to identify the melanomas.

RESULTS

On average, each dermatologist identified 24 of 59 melanomas (40%, range: 11-37). The number of correct picks was greater for dermatologists with moderate (mean: 28) or high (mean: 28) experience compared to beginners (mean 17; P < 0.001). In three of the 59 sets, none of the 26 dermatologists identified the melanoma. The mean grade of dermatoscopic atypia was 2.5 for nevi (95% CI: 2.4-2.6) and 3.0 for melanomas (95% CI: 2.9-3.1, P < 0.001).

LIMITATIONS

Rating dermatologists were informed that each quartet of images included one melanoma creating substantial deviation from a real-life situation.

CONCLUSION

A significant proportion of melanomas detected during follow-up cannot be differentiated from nevi at baseline. This necessitates the additional inclusion of less atypical lesions for monitoring.

An observational study regarding the rate of growth in vertical and radial growth phase superficial spreading melanomas

The natural history of superficial spreading melanomas (SSMs) involves the progression from a radial growth phase (RGP) to a vertical growth phase (VGP). Currently, a patient's history represents the only method to estimate the rate of tumor growth. The present study aimed to verify whether the estimated rate of growth (ROG) of SSMs with a RGP or VGP exhibited any differences, and to evaluate the possible implications for the most important prognostic determinants. ROG was quantified as the ratio between Breslow's thickness in millimeters (mm) and the time of tumor growth in months, defined as the time between the date that the patient had first noticed the lesion in which melanoma subsequently developed and the date on which the patient first felt this lesion changed. A total of 105 patients (58 male and 47 female) were studied. Of these, 66 had VGP-SSMs, whilst 39 had RGP-only SSMs (RGP-SSMs). No significant differences in age and gender were observed between these groups. The mean Breslow's thickness in patients with VGP-SSMs was significantly greater than in patients with RGP-SSMs (0.78±0.68 vs. 0.48±0.22 mm, P=0.0096). Similarly, the ROG was observed to be higher in VGP-SSM vs. RGP-SSM patients (0.13±0.16 vs. 0.065±0.09 mm/month, P=0.0244). In patients with VGP-SSMs, Breslow's thickness and ROG were significantly higher for tumors with a mitotic rate of ≥1 mitosis/mm² compared with those with <1 mitosis/mm² (1.15±0.96 vs. 0.56±0.30 mm, P=0.0005; and 0.188±0.20 vs. 0.09±0.12 mm/month, P=0.0228, respectively). According to these results, two subsets of SSMs exist: The first is characterized by the presence of mitosis and a higher ROG, while the second exhibits a more indolent behavior and is characterized by an RGP only. Given the differences in the Breslow's thickness and ROG, clinicians must be aware of the possible diagnostic delay in these subsets of melanoma that, differently from true nodular melanomas, generally fulfill the classical ABCD clinical criteria.

Melanoma progression

Tumours progress to fully malignant neoplasms through stages of development in a stepwise process. A carcinogenic stimulus such as UV light typically results in a large number of lesions, most of which are benign. Most such lesions will remain stable or regress, while a few will develop cytological and architectural atypia, placing them in a morphologically 'intermediate' category between wholly benign and fully malignant. It is important to categorise intermediate lesions, as they may be simulants, risk markers, and potential precursors of malignancy. Although many but not all malignancies arise in an evident precursor lesion, the vast majority of 'potential precursors' will not progress, as is evidenced by their vastly greater numbers in populations. Progression continues with the onset of malignancy including in metastatic disease. In melanoma as in other tumours, progression has been clearly related to the stepwise acquisition of genetic abnormalities. The first step is the activation of a single 'driver' oncogene, which is sufficient to induce a benign neoplasm whose growth is limited by oncogene-induced senescence driven by activated suppressors. In the intermediate lesions, additional genetic alterations occur such as additional driver mutations or heterozygous loss of suppressors due to copy number variation or other mechanisms. Fully malignant lesions are characterised by complete loss of relevant suppressors and by additional abnormalities, which together account for attributes of malignancy such as invasion and metastasis. Any of the steps of progression can be 'skipped', potentially due to telescoped progression or to alternative pathways. Although stages of progression might simply be viewed as markers of an individual's risk for developing subsequent stages, genetic associations that have been demonstrated among contiguous stages of progression in complex primary tumours and in their metastases would argue against this. For example, complex primary melanomas can be associated with remnants of earlier stage lesions both clinically and histologically. These include small symmetrical benign naevi and/or morphologically atypical dysplastic naevi ('precursor naevi'), and/or radial growth phase melanomas many of which may be inexorably progressive but lack competence for metastasis. Vertical growth phase is the stage of melanoma progression in which risk for metastasis may be acquired. This risk can be characterised statistically using prognostic attributes which at present are mostly clinicopathological, although in the future molecular profiling may contribute or even supplant these attributes. In metastatic disease, tumours can continue to progress, acquiring resistance to various therapeutic strategies which presents a considerable challenge to the efficacy of current promising therapeutic strategies.

Impact of oncogenic BRAF mutations and p16 expression on the growth rate of early melanomas and naevi in vivo

BACKGROUND

It is important to know what drives and arrests melanocytic growth in vivo but observations linking oncogenic mutations to growth rates of melanocytic neoplasms in vivo are sparse.

OBJECTIVES

To clarify the relationship between BRAF(V) (600E) mutations and p16 expression and the growth rate of melanocytic neoplasms in vivo.

METHODS

We measured the growth rate of 54 melanocytic lesions (26 melanomas, 28 naevi) in vivo with digital dermatoscopy and correlated it with BRAF(V) (600E) and p16 expression, and with dermatoscopic and histological patterns.

RESULTS

Melanomas grew faster than naevi (mean 2·7 vs. 0·8 mm(2) /year; P < 0·001) and the growth rate was faster in lesions with more nests (> 25% nests: 2·0 mm(2) /year vs. < 25% nests: 1·0 mm(2) /year; P = 0·036). Melanomas with the BRAF(V) (600E) mutation grew significantly faster than melanomas without the mutation (mean 3·36 vs. 1·60 mm(2) /year, P = 0·018). This effect of the BRAF(V) (600E) mutation on the growth rate was not observed in melanocytic naevi (mean 1·01 vs. 0·47 mm(2) /year, P = 0·274). Histopathologically, extensive nesting, larger nests and larger cell sizes were more common in melanocytic neoplasms with the BRAF(V) (600E) mutation than in those without the mutation. Melanomas expressing p16 had a slower growth rate than melanomas without p16 expression (2·27 vs. 4·34 mm(2) /year, P = 0·047). This effect was not observed in naevi (0·81 vs. 0·68 mm(2) /year, P = 0·836).

CONCLUSIONS

The expression of BRAF(V) (600E) and the loss of p16 accelerate the growth rate of early melanomas in vivo but not in melanocytic naevi. In comparison to melanocytic proliferations that lack the mutation, the epidermal melanocytes in lesions that harbour BRAF(V) (600E) mutations are larger and more frequently arranged in large nests.

An assessment of clinical pathways and missed opportunities for the diagnosis of nodular melanoma versus superficial spreading melanoma

BACKGROUND

Missed opportunities in the diagnosis of nodular melanoma (NM) carry high prognostic penalties due to the rapid rate of NM growth. To date, an assessment of the pathways to diagnosis of NM versus superficial spreading melanoma (SSM) specifically comparing numbers of opportunities missed to undertake biopsy has not been performed.

METHODS

A retrospective questionnaire of 120 patients (60 NM patients, age and sex matched to 60 SSM patients) from the Victorian Melanoma Service (VMS) database was undertaken to assess pathways to diagnosis. The numbers of opportunities missed to undertake a biopsy and doctor behaviour at such encounters were recorded. Diagnostic delay (overall, patient's and doctor's delay) in terms of time was assessed.

RESULTS

Significant differences in opportunities missed to make a diagnosis of NM compared to SSM were found. In all, 43% of NM were biopsied at a first encounter compared to 70% of SSM. All SSM were diagnosed within three reviews. Overall, 33% of NM required at least three and up six reviews until biopsy. Patients with NM were more likely than those with SSM to be reassured that their lesions were benign. No significant differences in terms of time delay to diagnosis between NM and SSM were found.

CONCLUSIONS

NM contributes disproportionately to melanoma mortality in Australia. Addressing earlier diagnosis of NM with renewed focus may make the biggest impact on the overall mortality of melanoma. The message that a period of observation is not appropriate for patients re-presenting with lesions of concern must be more effectively communicated.

The role of BRAF mutations in primary melanoma growth rate and survival

BACKGROUND

The clinical behaviour and prognosis of primary melanomas harbouring BRAF mutations is not fully understood.

OBJECTIVES

To investigate the effect of mutation status on primary melanoma growth rate and melanoma-specific survival (MSS).

METHODS

A prospective cohort of 196 patients with stage I-III primary cutaneous melanoma were followed for a median of 92 months, pre-dating the institution of BRAF inhibitor therapy. Clinicopathological variables were correlated with mutation status and hazard ratios (HRs) estimated for MSS.

RESULTS

Of 196 tumours, 77 (39.2%) were BRAF V600E, 10 (5.1%) BRAF V600K and 33 (16.8%) were NRAS mutant. BRAF V600E mutant melanomas were associated with favourable clinical characteristics and tended to be slower growing compared with BRAF V600K, NRAS mutant or BRAF/NRAS wild-type tumours (0.12 mm per month, 0.61 mm per month, 0.36 mm per month and 0.23 mm per month, respectively; P = 0.05). There were 39 melanoma deaths, and BRAF mutant melanomas were associated with poorer MSS in stage I-III disease [HR 2.60, 95% confidence interval (CI) 1.20-5.63; P = 0.02] and stage I-II disease (HR 3.39, 95% CI 1.12-10.22; P = 0.03) after adjusting for other prognostic variables. Considered separately, BRAF V600E mutant melanomas were strongly associated with MSS independently of thickness and nodal status (HR 3.89, 95% CI 1.67-9.09; P < 0.01) but BRAF V600K mutant tumours were not (HR 1.19, 95% CI 0.36-3.92; P = 0.77).

CONCLUSIONS

The presence of a BRAF mutation does not necessarily 'drive' more rapid tumour growth but is associated with poorer MSS in patients with early-stage disease.