REPORT
MULTIPLE BASAL CELL CARCINOMA IN TROPICAL AUSTRALIA D. CZARNECKI, M.B., B.S., N. COLLINS, F.A.C.D., P. CHOW, F.R.A.C.P., I. NICHOLSON, B.Sc, AND B. T A I T , PH.D.
Abstract No association between HLA DRI and the development of multiple basal cell carcinomas (BCC) was found among patients who had lived at least two-thirds of their lives in tbe tropics. The percentage of patients with multiple BCCS increased with age; this was different from what has been found in people living in the temperate zone of Australia. IntJ Dermatol 1992; 31:635-636.
none bad any recognized disease associated with the development of skin cancer. The control group consisted of 144 healthy white Australians.^ The HLA frequencies of the Cairns patients were compared with those of patients from tbe temperate zone of Australia (Melbourne). The two groups were matched for age and sex, but tbe main difference between tbe two groups was that the Melbourne pateints had lived less than 2 years on average in the tropics.
An association between HLA DRI and the development of multiple basal cell carcinotnas (BCCS) has recently been discovered.'"' The studies were carried out in the temperate zones of three continents, but the relative risk decreased the closer to the equator that the population lived.' This was probably because the increased amounts of ultraviolet light overrode any getietic susceptibility to the development of Bc:cs. Australia has a large white population livitig in the tropics, and the incidence of non-melanoma skin cancer is the highest in the world.'' A study was carried out to see if there was an associatioti between HLA DRI atid the development of multiple BCCs in people who had lived at least two-thirds of their lives iti the tropics.
RESULTS
A total of 310 patients with a confirmed non-melatioma skiti cancer were seen in otie year. There were 243 with a BCC and 67 with an SCC.^ Multiple BCCs had developed in 86 (36.8%) during their lives. In Table 1 is set out the percentage of people with tnultiple BCCs for different age groups. The percentage increased with age, and, after the age of 65 years, more than half of the people with BCCs had had three or tnore retnoved. There was tio association betweeti atiy HLA type and the development of tnultiple BCCs. The results of the HLA DR typing are set out in Table 2 and show that HLA DRI was not found tnore often than in the control group. The relative risk of having HLA DRI was 1. It should be noted that the frequency of HLA DRI is sitniInr among different Europeans,^'^'* whites living in the United States,''' and in Australia.' The control group was representative of the frequency of HLA DRI among whites in Australia. There was no difference in frequency of any class 1 antigen between the Melbourne and Cairns patients. The frequencies are set out in Table 3, and there was a highly significant difference in the frequency of HLA DRI between the two centres (P < 0.005). The association between HLA DRI and multiple BCCs was present in the temperate zone of Australia but not in the tropics.
Materials and Methods The population studied lived in Cairns, Australia, which is located at 16 degrees south. All consecutive patients seen by the only dermatologist in Cairns (N.C), over a 12 month period, had the following information recorded: age, sex, site of the prevalent skin cancer, histologic diagnosis, whether or not the patient had had multiple skin cancers (3 or more), and the number of years the patient had lived in the tropics. In addition, the HLA types of 21 people with multiple BCCS were determined and compared with those of a control population. The patients had had three or more histologically confirmed BCCS removed, but no other skin cancer. They had lived at least two-thirds of their lives in the tropics, they were not immunosuppressed, they were not related, and From the Repatriation General Hospital, Heidelberg, Victoria, the Frecker House, Gairns, Queensland, and the Tissue Typing Laboratory, Royal Melbourne Hospital, Parkville, Victoria, Australia.
DISCUSSION
This study found no association between HLA DRI and the development of multiple BCCs atnong patients who had lived two-thirds of their lives in the tropics. The association appears to be a weak one, which is oyerwhehned by high intensity of ultraviolet light (UVL).
Supported by a grant from the Skin and Psoriasis Foundation. Address for correspondence: D. Gzarnecki, M.B., B.S., Suite 1, 12 Floriston Road, Boronia 3155, Australia. 635
International Journal of Dermatology Vol. 3t, No. 9, Septemher t992
Table 1. Percentage of Multiple BCCs in Different Age Croups Age (years) Total Patients Multiple BCC Multiple BCC (as % of total)
85
2
22
56
60
52
0
3 12.5
15
17
24
9
0
26.8
28.3
46.2
35 18 51.4
U
0
56.3
0
0
Table 2. HLA DR Frequencies HLADR
•
Patients (N=2i)
Controls (N=]44)
Nmnber (%)
Nu,nber (%)
1
4
2
5
3
6 8 2
4 5 6 > 8 9
6 7 1 — 1
10
(19.0) (23.8) (28.6) (38.1) (9.5) (28.6) (33.3) (4.7) —
(4.7)
populations of Melbourne and Cairns are similar in ethnic composition and age distribution but the people of Cairns are exposed to considerably tnore UVL during their lives. The clitnate encourages outdoor activity and wearing of briefer, lighter clothing. The difference in exposure to UVL is the probable reason for the differences in the two centers. There has been a change in attitude to sun exposure in Australia since the Second World War.'" In Melbourne, people are exposed to tnore UVL through recreational activity, and it may be that the characteristics of BCC in Melbourne will becotne tnore like those in Cairns, i.e., a higher prevalence of BCC, a lower average age, and a higher prevalence of multiple lesions.
27 (18.9) 38 (26.7) 30 (21.3) 38 (26.7) 25 (22.8)''25 (22.8) 45 (31.5) (5.5) 8 4 (3.1) (0.0) 0
*Not significant. REFERENCES Table 3. HLA DR Frequencies in Patients HLADR 1 2 3 4 57 9
10
1.
Melbourne (n=21)
Cairns (n=21)
14 (66.7)«5 (23.8)
4 (19.0) 5 (23.8)
2.
3 (14.2) 5 (23.8) 4 (19.0) 3 (14.2) 5 (23.8) 1 (4.8) 1 (4.8)
6 (28.6)t
3.
—
8 (38.1)+
(9.5) (28.6)t 6 7 (33.3) 1 (4.8)
2
4.
5.
— 1
(4.8)
* Statistically significant; Chi square, 9.7, P
MULTIPLE BASAL CELL CARCINOMA IN TROPICAL AUSTRALIA D. CZARNECKI, M.B., B.S., N. COLLINS, F.A.C.D., P. CHOW, F.R.A.C.P., I. NICHOLSON, B.Sc, AND B. T A I T , PH.D.
Abstract No association between HLA DRI and the development of multiple basal cell carcinomas (BCC) was found among patients who had lived at least two-thirds of their lives in tbe tropics. The percentage of patients with multiple BCCS increased with age; this was different from what has been found in people living in the temperate zone of Australia. IntJ Dermatol 1992; 31:635-636.
none bad any recognized disease associated with the development of skin cancer. The control group consisted of 144 healthy white Australians.^ The HLA frequencies of the Cairns patients were compared with those of patients from tbe temperate zone of Australia (Melbourne). The two groups were matched for age and sex, but tbe main difference between tbe two groups was that the Melbourne pateints had lived less than 2 years on average in the tropics.
An association between HLA DRI and the development of multiple basal cell carcinotnas (BCCS) has recently been discovered.'"' The studies were carried out in the temperate zones of three continents, but the relative risk decreased the closer to the equator that the population lived.' This was probably because the increased amounts of ultraviolet light overrode any getietic susceptibility to the development of Bc:cs. Australia has a large white population livitig in the tropics, and the incidence of non-melanoma skin cancer is the highest in the world.'' A study was carried out to see if there was an associatioti between HLA DRI atid the development of multiple BCCs in people who had lived at least two-thirds of their lives iti the tropics.
RESULTS
A total of 310 patients with a confirmed non-melatioma skiti cancer were seen in otie year. There were 243 with a BCC and 67 with an SCC.^ Multiple BCCs had developed in 86 (36.8%) during their lives. In Table 1 is set out the percentage of people with tnultiple BCCs for different age groups. The percentage increased with age, and, after the age of 65 years, more than half of the people with BCCs had had three or tnore retnoved. There was tio association betweeti atiy HLA type and the development of tnultiple BCCs. The results of the HLA DR typing are set out in Table 2 and show that HLA DRI was not found tnore often than in the control group. The relative risk of having HLA DRI was 1. It should be noted that the frequency of HLA DRI is sitniInr among different Europeans,^'^'* whites living in the United States,''' and in Australia.' The control group was representative of the frequency of HLA DRI among whites in Australia. There was no difference in frequency of any class 1 antigen between the Melbourne and Cairns patients. The frequencies are set out in Table 3, and there was a highly significant difference in the frequency of HLA DRI between the two centres (P < 0.005). The association between HLA DRI and multiple BCCs was present in the temperate zone of Australia but not in the tropics.
Materials and Methods The population studied lived in Cairns, Australia, which is located at 16 degrees south. All consecutive patients seen by the only dermatologist in Cairns (N.C), over a 12 month period, had the following information recorded: age, sex, site of the prevalent skin cancer, histologic diagnosis, whether or not the patient had had multiple skin cancers (3 or more), and the number of years the patient had lived in the tropics. In addition, the HLA types of 21 people with multiple BCCS were determined and compared with those of a control population. The patients had had three or more histologically confirmed BCCS removed, but no other skin cancer. They had lived at least two-thirds of their lives in the tropics, they were not immunosuppressed, they were not related, and From the Repatriation General Hospital, Heidelberg, Victoria, the Frecker House, Gairns, Queensland, and the Tissue Typing Laboratory, Royal Melbourne Hospital, Parkville, Victoria, Australia.
DISCUSSION
This study found no association between HLA DRI and the development of multiple BCCs atnong patients who had lived two-thirds of their lives in the tropics. The association appears to be a weak one, which is oyerwhehned by high intensity of ultraviolet light (UVL).
Supported by a grant from the Skin and Psoriasis Foundation. Address for correspondence: D. Gzarnecki, M.B., B.S., Suite 1, 12 Floriston Road, Boronia 3155, Australia. 635
International Journal of Dermatology Vol. 3t, No. 9, Septemher t992
Table 1. Percentage of Multiple BCCs in Different Age Croups Age (years) Total Patients Multiple BCC Multiple BCC (as % of total)
85
2
22
56
60
52
0
3 12.5
15
17
24
9
0
26.8
28.3
46.2
35 18 51.4
U
0
56.3
0
0
Table 2. HLA DR Frequencies HLADR
•
Patients (N=2i)
Controls (N=]44)
Nmnber (%)
Nu,nber (%)
1
4
2
5
3
6 8 2
4 5 6 > 8 9
6 7 1 — 1
10
(19.0) (23.8) (28.6) (38.1) (9.5) (28.6) (33.3) (4.7) —
(4.7)
populations of Melbourne and Cairns are similar in ethnic composition and age distribution but the people of Cairns are exposed to considerably tnore UVL during their lives. The clitnate encourages outdoor activity and wearing of briefer, lighter clothing. The difference in exposure to UVL is the probable reason for the differences in the two centers. There has been a change in attitude to sun exposure in Australia since the Second World War.'" In Melbourne, people are exposed to tnore UVL through recreational activity, and it may be that the characteristics of BCC in Melbourne will becotne tnore like those in Cairns, i.e., a higher prevalence of BCC, a lower average age, and a higher prevalence of multiple lesions.
27 (18.9) 38 (26.7) 30 (21.3) 38 (26.7) 25 (22.8)''25 (22.8) 45 (31.5) (5.5) 8 4 (3.1) (0.0) 0
*Not significant. REFERENCES Table 3. HLA DR Frequencies in Patients HLADR 1 2 3 4 57 9
10
1.
Melbourne (n=21)
Cairns (n=21)
14 (66.7)«5 (23.8)
4 (19.0) 5 (23.8)
2.
3 (14.2) 5 (23.8) 4 (19.0) 3 (14.2) 5 (23.8) 1 (4.8) 1 (4.8)
6 (28.6)t
3.
—
8 (38.1)+
(9.5) (28.6)t 6 7 (33.3) 1 (4.8)
2
4.
5.
— 1
(4.8)
* Statistically significant; Chi square, 9.7, P
