Incidence of cutaneous malignant melanoma in Granada (Spain) 1985-1992

1. Incidence of cutaneous malignant melanoma in Granada (Spain) 1985-1992 Ricardo Ocaña-Riola, PhD Andalusian School of Public Health Granada - Spain

2. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública The author Ricardo Ocaña-Riola Professor of Biostatistics Andalusian School of Public Health E-mail ricardo@easp.es Web www.easp.es Address for correspondence Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Campus Universitario de Cartuja, s/n Apdo de Correos 2070 18080 Granada (Spain) References

3. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Framework • Tumours derived from melanocytes • The commonest in humans • Most of them are benign • They sometimes are converted into malignant melanomas • Relevance of malignant melanoma • High incidence among younger cohorts • Increase in its incidence

4. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Framework Source: Armstrong and Kricker, 1994

5. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Framework • Results from international studies • Different world wide incidence rates • Different world wide survival rates • Different risk and prognosis factors • Why population-based studies? • Knowledge of our population • Contribution to improve health care

6. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Objectives • Main objective • Specific objectives • Population-based study of cutaneous malignantmelanoma in the Granada province , 1985-1992 • 1. To estimate the standardised incidence rates • 2. To describe the incidence trends • 3. To study the incidence geographical pattern • 4. To describe the characteristics of the incident cases

7. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Methodology

8. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Scope of the study

9. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Design, patients and sources • Descriptive study • Patients • All cases diagnosed from 1985 to 1992 • 247 incident cases of melanoma • All of them live in the Granada province • Source of information • Granada Cancer Registry

10. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Variables • Sex • Age (years) • Anatomic site • Histological type (ICD-O) • Clark level (I-V) • Breslow thickness (mm)

11. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Statistical data analysis • World population standardised incident rates • ASRW (x100.000 inhabitants) • To compare different populations • Univariate and bivariate analysis • Descriptive tables • Chi-squared test • T-Student test

12. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Statistical data analysis • Trend analysis • Smoothing (moving averages) • To see the real trend of incidence • To delete random fluctuations into the time series • Standardised rates by periods • 1985-87, 1988-1990 y 1991-1992 • To quantify the incidence rates change

13. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Statistical data analysis • Geographical analysis • Standardised Incidence Rate (SIR) • Calculated by the Indirect method • SIR=Observed/Expected • Population of reference: Granada province • Bayesian models • Smoothing SIR • To control extra-Poisson variability • To detect clusters

14. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Statistical software • S-PLUS • Descriptive analysis • Trends analysis • WinBUGS • Bayesian models • EpiMap • Smoothing incidence maps

15. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Results and Discussion

16. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Incidence rates Cutaneous Malignant Melanoma Granada, 1985-1992.

17. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Incidence rates • Medium-low rates world-wide • Different to other countries • Different risk factors • Skin type (Zanetti et al, 1992) • Sun exposure (Aase and Bentham, 1996) • Incidence similar to rates in other Spanish cancer registries

18. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública World wide incidence rates MALES World maximum European maximum Spain European minimum World minimum ASRW (x100.000) Source: Cancer Incidence in Five Continents

19. © Ricardo Ocaña-Riola FEMALES World maximum European maximum Spain European minimum World minimum ASRW (x100.000) Source: Cancer Incidence in Five Continents Escuela Andaluza de Salud Pública World wide incidence rates

20. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Trends in melanoma incidence Cutaneous Malignant Melanoma (ASRW) Granada, 1985-1992.

21. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Trends in melanoma incidence • Increasing trends • Average annual increase around 4% • Similar increase in other countries • Hypothesis for this fact • Change in sun exposure (Pukkala, 1995) • Change in health care practices

22. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública GEOGRAPHICAL PATTERN Cutaneous melanoma (Granada, 1985-1992) SIR Menos de 0.01 0.01 - 0.61 0.62 - 0.82 0.83 - 0.89 0.90 - 1.07 1.08 - 1.31 1.32 - 2.15 Ms de 2.15

23. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Characteristics of incident cases Cutaneous Malignant Melanoma Granada, 1985-1992

24. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Characteristics of incident cases Cutaneous Malignant Melanoma Granada, 1985-1992

25. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Characteristics of incident cases • Incidence among younger cohorts • 1/3 of cases under 45 years • Contrast to other skin tumours • Melanoma non related to cumulative dosage of sun exposure (Zanetti et al, 1992) • Higher incidence among females • Similar to other European Registries • Different to EEUU

26. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Characteristics of incident cases • Male and female dissimilarities • Anatomic site • Trunk in males • Lower limbs in females • Are the differences due to clothes? (Aase et al, 1996) • Clark level and Breslow • Lower in females • Cultural differences between gender • Early diagnosis (Armstrong et al, 1994)

27. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Conclusions

28. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Conclusions • Medium incidence rates world-wide • The highest incidence rates are located in the city of Granada and all the municipalities around it • There was an increasing trend in the incidence of melanoma from 1985 to 1992

29. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Conclusions More frequent characteristics of incident cases Cutaneous malignant melanoma Granada, 1985-1992 • MALES • 57 years old • MS Superficial • Trunk • Medium-High • Medium-High • FEMALES • 53 years old • MS Superficial • Lower limbs • Low-Medium • Low-Medium • CHARACTERISTIC • Age • Histological type • Anatomic site • Clark level • Breslow

30. © Ricardo Ocaña-Riola Escuela Andaluza de Salud Pública Conclusions This information, which corresponds to the province’s whole population, might guide health policies contributing to disease prevention and to a better care. Because of the increase in incidence rates and the high percentage of cases diagnosed at advanced stages, it is advised that prevention campaigns are addressed to the Granada population.