Characteristics, treatment patterns, and survival outcomes of primary GI melanoma cases compared to cutaneous melanoma, SEER:

Transcription

1 Characteristics, treatment patterns, and survival outcomes of primary GI melanoma cases compared to cutaneous melanoma, SEER: Amanda Kahl, MPH Mary E. Charlton, PhD, Imran Hassan, MD, Paolo Goffredo, MD, Catherine Chioreso, MPH, & Chi Lin, MD Oral Presentation, NAACCR June 14, 2018

2 Background Melanoma: ~10% of all primary cancer diagnoses in US 5 th and 6 th most common cancer in males and females Rare cases of primary gastrointestinal (GI) melanoma Reported to arise from mucosal membranes of the Esophagus Stomach Small intestine Colon Rectum Anus

3 Background 60% of metastatic skin melanomas have GI involvement at autopsy HOWEVER, several studies reported GI melanoma in the absence of skin melanoma But HOW?? Stem cells differentiating into melanocytes in the GI tract Cell migration

4 Primary GI Melanoma Most studies of GI melanoma have been based on case series Population-based cancer registries allow for examination of rare cancers over long periods of time

5 Study objective Compare characteristics, treatment, and survival between skin melanoma and primary GI melanoma Including sites of the esophagus, stomach, small intestine, colon, rectum, and anus

6 INCLUSION CRITERIA Diagnosed between Histology of GI melanoma sites: Esophagus (C150-C159) Stomach (C160-C169) Small intestine (C170-C179) Colon (C180-C189, C260) Rectum (C199, C209) Anus (C210, C211, C212, C218) Skin melanoma: C440-C449 First primary malignant melanoma: - GI melanoma N=828 - Skin melanoma N=304,797 Not reported via autopsy or death certificate - GI melanoma N=827 - Skin melanoma N=304,082 Ages GI melanoma N=827 - Skin melanoma N=302,194 Excluded: GI melanoma N=1 Skin melanoma N=715 Excluded: GI melanoma N=0 Skin melanoma N=1,888

7 Methods SEER*Stat used to extract patient, tumor and treatment variables Statistical analysis performed in SAS Chi-square tests for bivariate analyses Cause-specific Survival Cox proportional hazard models Incidence rates ( ) were calculated in SEER*Stat and analyzed in Joinpoint

8 Results

9 GI Melanoma Incidence Rate, SEER

10 Skin Melanoma vs GI Melanoma Patient characteristics between GI melanoma and skin melanoma, Cutaneous Melanoma GI Melanoma (N=302,194) (N=827) N % N % p-value Age at diagnosis ,994 33% 95 12% < ,842 42% % ,358 26% % Sex Female 135,090 45% % < Male 167,104 55% % Race White 285,387 94% % < Non-White 16,807 6% % Married Yes 156,993 52% % No 145,201 48% % Year of diagnosis ,754 9% 68 8% ,102 8% 62 8% ,936 16% % ,313 31% % ,089 37% %

11 Skin Melanoma vs GI Melanoma Tumor characteristics between patients with GI melanoma and skin melanoma, Cutaneous Melanoma GI Melanoma (N=302,194) (N=827) N % N % p-value SEER Summary Localized 248,669 82% % < Stage Regional 28,033 9% % Distant 11,675 4% % Unstaged 13,817 5% 93 11% Tumor Size* <2 mm/cm 216,272 72% 85 10% - 2-<5 mm/ cm 24,789 8% % >=5 mm/cm 10,816 4% % Unknown 50,317 17% % *Tumor size is thickness in mm for cutaneous melanoma and size in cm for GI melanom

12 Skin Melanoma vs GI Melanoma Treatment characteristics between patients with GI melanoma and skin melanoma, Surgery* Cutaneous Melanoma GI Melanoma (N=257,391) (N=827) N % N % p-value Local tumor % <0.000 excision 1 Major resection % Surgery, NOS % 23 3% None or local tumor destruction only % % Unknown % 1 0.2% Radiation* Yes % % < No/Unknown % % Chemotherap Yes % % <0.000 y* *Due to the large number of unknown surgery for cases diagnosed prior to 1988, they were excluded No/Unknown from the treatment variables 98% % 1

13 Anorectal vs Other GI site Melanoma Characteristics between anorectal and other GI site melanoma, Anorectal Melanoma Other GI Melanoma Sites (N=688) (N=139) N % N % p- value GI cancer sites Esophagus % - Stomach % Intestine % Colon % Rectum % - - Anus % - -

14 Anorectal vs Other GI site Melanoma Patient characteristics between anorectal and other GI site melanoma, Anorectal Melanoma Other GI Melanoma Sites (N=688) (N=139) N % N % p- value Age at diagnosis % 16 12% % 57 41% % 66 48% Sex Female % 62 45% Male % 77 55% Race White % % Non-White % 16 12% Married Yes % 73 53% No % 66 48% Year of diagnosis % 14 10% % 10 7% % 21 15%

15 Anorectal vs Other GI site Melanoma Tumor characteristics between anorectal and other GI site melanoma, Anorectal Other GI Melanoma Melanoma Sites (N=688) (N=139) N % N % SEER Summary Localized % 40 29% Stage Regional % 23 17% Distant % 60 43% Unstaged 77 11% 16 12% Tumor Size <2 cm 83 12% 2 1% 2-<5 cm % 29 21% >=5 cm % 48 35% Unknown % 60 43% p- value <. 0001

16 Anorectal vs Other GI site Melanoma Treatment characteristics between between anorectal and other GI site melanoma, Surgery* Other GI Anorectal Melanoma Melanoma Sites (N=688) (N=139) N % N % p-value Local tumor excision Major resection % 71 57% Surgery, NOS 22 4% 1 1% None or local tumor destruction only % 4 3% < % 49 39% Unknown 1 0% - - Radiation* Yes % 18 14% No/Unknown % % Chemotherap y* Yes % 25 20% No/Unknown % % *Due to the large number of unknown surgery for cases diagnosed prior to 1988, they were excluded from the treatment variables

17 Kaplan Meier Cause-Specific Survival Curves

18 Survival of GI melanoma and skin melanoma patients,

19 Survival of localized GI melanoma and skin melanoma patients, Localized

20 Survival of regional GI melanoma and skin melanoma patients, Regional

21 Survival of distant GI melanoma and skin melanoma patients, Distant

22 Cause-Specific Survival (CSS) Hazard Models

23 CSS adjusted hazard model including both GI melanoma and skin melanoma (N=228,927) *Surgery NOS or Unknown Surgery; Unstaged, and Unknown size were excluded from model All cases HR 95% CI Cancer Type Cutaneous Melanoma 0.29 (0.25, 0.33) Anorectal Melanoma 1.00 REF Other GI site Melanoma 0.58 (0.42, 0.81) Age at diagnosis (0.35, 0.38) (0.53, 0.56) REF Sex Female 0.67 (0.65, 0.69) Male 1.00 REF Race White 1.00 REF Non-White 0.74 (0.68, 0.80) Married Yes 1.00 REF No 1.08 (1.05, 1.11) Year of diagnosis REF (0.80, 0.89) (0.78, 0.87) (0.71, 0.81) SEER Summary Stage Localized 1.00 REF

24 CSS adjusted hazard model including both GI melanoma and skin melanoma (N=228,927) *Surgery NOS or Unknown Surgery; Unstaged, and Unknown size were excluded from model All cases HR 95% CI Surgery Local tumor excision 1.00 REF Major resection 1.37 (1.30, 1.44) None or local tumor destruction only 1.54 (1.41, 1.68) Radiation Yes 1.00 REF No/Unknown 0.44 (0.41, 0.46) Chemotherapy Yes 1.00 REF No/Unknown 0.43 (0.41, 0.46)

25 CSS adjusted hazard model of GI melanoma (N=440) *Surgery NOS or Unknown Surgery; Unstaged, and Unknown size were excluded from model GI Melanoma HR 95% CI Cancer Type Anorectal Melanoma 1.00 REF Other GI site Melanoma 0.92 (0.63, 1.34) Age at diagnosis (0.38, 0.84) (0.67, 1.15) REF Sex Female 1.02 (0.80, 1.32) Male 1.00 REF Race White 1.00 REF Non-White 1.12 (0.82, 1.53) Married Yes 1.00 REF No 0.82 (0.65, 1.05) Year of diagnosis REF (0.59, 1.62) (0.51, 1.32) (0.44, 1.16) SEER Summary Stage Localized 1.00 REF

26 CSS adjusted hazard model of GI melanoma (N=440) *Surgery NOS or Unknown Surgery; Unstaged, and Unknown size were excluded from model GI Melanoma HR 95% CI Tumor Size <2 cm 1.00 REF 2-<5 cm 1.13 (0.80, 1.61) >=5 cm 1.07 (0.72, 1.59) Surgery Local tumor excision 1.00 REF Major resection 0.92 (0.67, 1.27) None or local tumor destruction only 1.62 (1.04, 2.51) Radiation Yes 1.00 REF No/Unknown 1.08 (0.77, 1.52) Chemothera py Yes 1.00 REF No/Unknown 1.03 (0.74, 1.43)

27 Conclusions Incidence of GI melanoma has increased over time Skin melanoma has better prognosis overall and at every stage compared to GI melanoma Local tumor excision is no better than major resection for GI melanoma

28 Limitations & Strengths Limitations Small number of GI melanomas in individual sites Cases with GI melanoma may have undiagnosed primary skin melanoma Chemotherapy and radiation variables have sensitivity of 68% and 80%, respectively Strengths SEER data provide detailed information about cancer stage and treatment at time of diagnosis One of the first population based studies that characterizes the epidemiology, treatment, and survival of primary GI melanoma that includes sites of the esophagus, stomach, small intestine, colon, rectum, and anus compared to skin melanoma.

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