Duration of acceptable delay between the time of diagnosis and treatment of melanoma, cutaneous squamous cell carcinoma and basal cell carcinoma

Dear Editor,

Since tumours are usually treated soon after they are detected, there is limited guidance regarding when prompt treatment of skin cancer is important, and when delay is acceptable. Further delays may not be planned but rather attributable to inadvertent or uncontrollable patient or insurance-related factors,^1–7 or emergencies like pandemics.⁸

When mean delays are of long duration, some guidance is necessary to help dermatologists minimize tumour-mediated tissue disfigurement, functional and sensory loss, metastasis and death. Given the impracticality of controlled studies of treatment delay, it is appropriate to consider expert opinion.

This cross-sectional survey of American College of Mohs Surgery (ACMS) members elicited expert opinion about the acceptable post-diagnosis delay before treatment of basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC) and melanoma. This study was deemed exempt by the Western Institutional Review Board under 45 CFR 46.104(d)(2).

For common presentations of BCC, cSCC and melanoma, participants were asked to note the acceptable days of delay between diagnosis (e.g. by biopsy) and treatment in five scenarios: (1) for a family member or close friend; (2) per standard office or institution policy; (3) per standard national US guidelines; (4) in an epidemic/pandemic with appropriate PPE available; and (5) in an epidemic/pandemic without appropriate PPE.

Three hundred and eighty-nine responses were recorded (52.8% of the 737 who accessed the link). In addition to mean days of acceptable delay, Fig. 1 displays the range of responses within one and two standard deviations of the mean, respectively. Within each tumour type, tumours with a greater risk of harm were associated with briefer acceptable delay. Without exception, the two standard deviation range included zero, and so was useful primarily for describing the upper bound of acceptable delay. The lowest acceptable upper bound, 32 days, was associated with invasive melanoma ≥0.8 mm depth in either a family member or close friend, or per standard office or institution policy. The highest, 254 days, was associated with non-high risk BCC appropriate for surgical excision during a pandemic when appropriate PPE is not available.

Figure 1.

Average acceptable days to delay treatment for BCC, cSCC and melanoma. For each of the three types of skin cancer, the acceptable number of days of delay for five specific circumstances are shown (e.g. family or close friend, standard office or institution policy). For each of the five circumstances, the average acceptable days of delay for three different presentations of the skin cancer are depicted, ranging from least to greatest severity. Each line displays the mean number of days, as well as the range of responses within one and two standard deviations of the mean. Abbreviations: BCC, basal cell carcinoma; cSCC, cutaneous squamous cell carcinoma.

Pairwise analyses between scenarios within the same tumour type are presented in Fig. 2. For all comparisons, a significantly longer delay (P < 0.001; range 7–21 days) was appropriate in a pandemic when PPE is not available compared to when it is. In a pandemic when PPE is available, significant delay beyond standard national guidelines was acceptable for all BCCs (4–13 days, P ≤ 0.05), cSCC in situ (9 days, P = 0.028) and melanoma in situ (5 days, P = 0.034). For invasive SCCs and melanomas, no further delay was deemed appropriate.

Figure 2.

Pairwise comparisons of acceptable days to delay treatment between specific circumstances (e.g. family or close friend, standard office or institution policy) for different presentations of BCC, cSCC and melanoma (ranging from least to greatest severity). The number in each box is the difference in the acceptable days to delay between the condition in the column as vs. the condition in the top row. Positive values indicate a greater number of days are acceptable in the column condition, whereas negative values indicate a fewer number of days are acceptable in the column condition. For example, for ‘BCC appropriate for surgical excision that is other than high risk’, the average number of acceptable days to delay treatment for a family member or close friend is 46 days less than for circumstances when PPE is not available. Abbreviations: BCC, basal cell carcinoma; cSCC, cutaneous squamous cell carcinoma.

Although skin cancer experts differ regarding the treatment delay they deem acceptable, they are aligned in their estimation of appropriate relative delay across different scenarios. Overall, experts believed that less delay in treatment was appropriate for malignancies with greater overall risk of harm, such as SCCs and melanoma.

Since respondents were in the United States, the results may not be globally generalizable. Additionally, factors beyond patient or physician control, such as pandemics and emergencies, may limit physicians’ ability to safely accommodate patients.

In summary, there is wide variation in the duration of delay between diagnosis and treatment of skin cancer deemed acceptable by experts. Future investigations may detect and track growth in skin cancers with low risk of metastasis, and estimate the rate of change in size, as well as the time-associated risk of functional loss and metastasis. If such research is conducted, repeating the current survey in 5–10 years may reveal greater consensus regarding appropriate delay. In the meantime, the conclusions of this study can not only inform the timing of cancer care in routine circumstances but also in resource-constrained environments.

Data Availability Statement

Data available upon reasonable request.