jacob arthurin 1827 first coined the term  rodent ulcer  to describe what we now know as a basal cell carcinoma ( bcc ) .
it is the most common cutaneous malignancy worldwide , accounting for 6575% of all skin cancers .
gross differences are noted in the percentage of skin cancer in the asians ( 24% ) and blacks ( 1 - 2% ) as compared to the caucasians ( 3540% ) .
although the incidence of skin cancers in india is lower as compared to the western world , absolute number of cases may be significant due to large population .
the existing literature on bcc in india is scant with lack of clinical studies with statistical analysis .
so , this study was undertaken to fill this deficit in literature of bcc with focus on epidemiology , risk factors , and clinical and pathological aspects of the disease .
bcc is a nonmelanocytic skin malignancy arising from basal cells of the epidermis or follicular structures and is seen mostly on sun exposed areas , especially head and neck , occasionally over the trunk and limbs , and rarely on the palms , soles , mucous membranes , and genitals [ 4 , 5 ] .
recently , it has been indicated that bcc occurrence is higher along embryonic fusion planes as compared to other areas of the midface , evidence that supports this hypothesis for bcc pathogenesis .
ninety - five percent of these neoplasms occur in patients aged more than 40 years , although cases in childhood and congenital basal cell epitheliomas have been reported [ 79 ] . in children ,
it is usually associated with a genetic defect , such as basal cell nevus syndrome , xeroderma pigmentosum , nevus sebaceous , epidermodysplasia verruciformis , rombo syndrome , or bazex syndrome .
sunlight is the most frequent association with development of bcc ; risk correlates with the amount and nature of accumulated exposure , especially during childhood .
a latency period of 2050 years is typical between the time of ultraviolet ( uv ) damage and bcc clinical onset .
uvb is believed to play a greater role in the development of bcc than uva . in a 2012 systematic review and meta - analysis of 12 studies with 9328 cases of nonmelanoma skin cancer , wehner et al . found that indoor tanning was associated with a significantly increased risk of both basal and squamous cell skin cancers .
apart from uvr , x - ray and grenz ray exposure is also linked with development of bcc .
arsenic has been used as a medicinal agent , predominantly the fowler solution of potassium arsenite , which was used to treat many disorders , including asthma and psoriasis , and is linked to the risk of development of multiple malignancies after a long latency period spanning many years .
the risk of developing new nonmelanoma skin cancer is reported to be 35% at 3 years and 50% at 5 years after an initial skin cancer diagnosis .
a study among adults in the united states reports a strong association between excessive alcohol drinking and higher incidence of sunburn , suggesting a linkage between alcohol consumption and skin cancer .
a hospital based study was conducted at a tertiary care hospital situated in punjab , north india , from 2011 to 2013 .
patients of all ages attending skin outpatient department with suspected lesions were screened for bcc after taking an informed written consent .
patients with histopathologically confirmed bcc were enrolled in the study . detailed history with recording of various patient variables like age , gender , duration of symptoms , fitzpatrick skin phototype , skin color , average daily sun exposure ( hours / day ) , occupation , residence place ( rural or urban ) , exposure to chemicals including pesticides , radiation exposure history , treatment with psoralen uva ( puva ) or narrow band uvb ( nbuvb ) , smoking , alcohol intake , history of personal or family history of skin cancers , personal or family history of other cancers , history of genetic disorder like xeroderma pigmentosum , albinism , and history of previous treatment .
clinical examination was done with data collection on various tumor variables which included the following : size , location , number , morphological subtype , and pigmentation . for descriptive purposes ,
the lesions were classified based on size into small ( less than 1  cm in diameter ) , medium ( 1 - 2  cm in diameter ) , and large ( > 2  cm in diameter ) .
investigations included complete blood count with differentials , bleeding time , clotting time , renal function tests , liver function tests , and viral markers .
diagnosis was confirmed by histopathological examination of biopsy specimen with documentation of histopathological variant . to analyze the results , descriptive statistics such as mean ,
various analytic tests such as  test , p value , and t - test were used .
a total of 36 histopathologically confirmed cases of bcc were enrolled in the study from 2011 to 2013 .
an increase was seen in absolute number of cases diagnosed per year with 9 , 11 , and 16 patients in 2011 , 2012 , and 2013 , respectively ( figure 6 ) . out of these patients ,
males were 36.1% ( 13/36 ) and females were 63.9% ( 23/36 ) with m  :  f being equal to 0.57  :  1 ( figure 7 ) .
age of the affected cases ranged from 29 to 92 years of age . the mean  sd age of the patients was 60.9  14.2 years ( 65.92  14.35 years for males and 57.96  13.54 years in case of females ) .
although the difference in mean age between males and females was not statistically significant ( data was analyzed using unpaired t - test ) , it carries a clinical relevance as females tend to seek medical care earlier than males for suspicious , asymptomatic , and cosmetically disfiguring lesions .
the greatest number of patients was in the age group of 6180 years ( 47.2% ) followed by 4160 years ( 38.95% ) , 2140 years ( 8.3% ) , and 81100 years ( 5.6% ) , respectively ( figure 8) .
the youngest age of presentation in case of females was 29 years , while in males the corresponding age was 45 years .
correlation between gender and age group was not statistically significant ( fisher exact test p value being 0.177 ) , implying that these two variables are independent ( table 1 ) . out of all patients , 69.4% ( 25/36 ) hailed from rural areas .
a statistically significant association was seen between duration of disease and illiteracy (  value = 6.95 and p value = 0.01 ) .
this meant that illiterate patients present at a later stage of disease attributable to lack of awareness about disease entity .
farming was the main occupation among male patients ( 92.3% ) , while housekeeping was the major job among female patients ( 95.7% ) .
the duration of disease before seeking medical care ranged from 5 months to as long as 15 years , with mean duration being 4.7 years .
the average duration of sun exposure was 6 hours / day in case of males and 2.91 hours / day in female patients .
this difference in duration of sun exposure was statistically significant ( t - value being 6.71 and p value = 0.000 ) ( table 3 ) .
however , the females were intermittently exposed to high intensity sunlight due to work in open kitchens and fields during sowing and harvesting seasons .
none of the patients had been taking photoprotective measures such as use of sunscreens and protective clothing .
there was no history of treatment with puva or nbuvb in any of the study cases .
no patient had features suggestive of genodermatoses associated with predilection for cutaneous malignancies like xeroderma pigmentosa , albinism , and so forth .
out of 36 patients , one ( 2.8% ) had been previously treated for breast and endometrial carcinoma .
all the cases belonged to fitzpatrick skin types iii and iv ( calculated via fitzpatrick scoring scale ) .
out of total 36 patients , two ( 5.6% ) had 2 lesions at the time of presentation .
one female ( 2.8% ) patient had multiple lesions over face followed by development of ulcerative growths on ear and mons pubis .
she was later diagnosed with bcc having noncontiguous and distant cutaneous metastasis ( figure 1 ) .
the size of lesions ranged from as small as 0.5  cm to 5  cm in diameter .
the size of lesions was found to have a statistically significant association with duration of disease (  = 11.10 ; p value = 0.004 ) ( table 4 ) .
the distribution of lesions was as follows : nose ( 50% ) , cheeks ( 22.2% ) , ear and preauricular area ( 13.9% ) , lower eyelid ( 13.9% ) , temporal area ( 5.6% ) , upper lip ( 2.8% ) , forehead ( 2.8% ) , scalp ( 2.8% ) , and mons pubis ( 2.8% ) ( table 5 ) .
nose was the most significant site of involvement in our study (  = 14.43 ; p value = 0.01 , while corresponding values without involving nose as site of bcc were 1.00 and 0.80 ) .
the most common morphological subtype of bcc was nodular / noduloulcerative growth ( 77.8% ) ( figures 1 and 2 ) .
a significant percentage of bcc was clinically pigmented ( 22.2% ) ( table 6 ) .
the most common histopathological variant was nodular subtype ( 77.8% ) with a significant proportion of tumors being pigmented ( 16.7% ) ( table 7 ) .
other subtypes included basosquamous ( 8.3% ) , micronodular ( 2.8% ) , morpheaform ( 2.8% ) , keratotic ( 2.8% ) , and adenoid ( 2.8% ) bcc and bcc with adnexal differentiation ( 2.8% ) .
consequently , most of the studies have focused on white populations in europe , usa , and australia with scarcity of data from developing countries ( table 9 ) .
estimates of the incidence of bcc are imprecise since there is no cancer registry that collects data on bcc .
although incidence rates of bcc vary significantly according to the ethnicity and geographic location , most studies show a rising trend in its incidence worldwide . this has been largely attributed to fair complexion and ozone layer depletion resulting in increased uv radiation reaching earth 's surface .
factors other than the mentioned above need to be searched and verified as darker skin complexion in indians should otherwise be protective against bcc .
moreover , ozone layer destruction is most evident over the temperate and polar regions , while india is a tropical country [ 15 , 16 ] .
this finding highlights the need for early institution of uv protection and skin cancer screening in the pediatric and young adult population . however , there was no case below the age of 20 years in our study .
relative risk of bcc is more for children who have undergone radiation therapy for enlarged thymus   or neoplasms such as medulloblastoma .
bccs are more common in males as reported in most studies worldwide , presumably due to greater occupational and recreational exposure to ultraviolet radiation ( uvr ) .
however , an unusual female preponderance was noticed in our study which is consistent with findings of another indian series .
indian housewives especially rural women work in open kitchen ( figure 4 ) during their household chores and work in the fields during sowing and harvesting seasons exposing them to intermittent , high intensity uvr .
it might explain higher frequency of bcc in females in our study as intermittent rather than constant , cumulative uvr exposure is implicated in the pathogenesis of bcc .
this female predilection may also be attributed to the changes in cultural practices like  veil  custom ( figure 5 ) , structurally thinner skin with lower collagen density in the dermis when compared to men .
the most commonly affected age group in our study was 6180 years ( 47.2% ) followed by 4160 years ( 38.95% ) , 2140 years ( 8.3% ) , and 81100 years ( 5.6% ) .
the cases belonged to age ranging from 29 to 92 years which is similar to study published from north india .
higher rates of occurrence of bcc among elderly may be due to cumulative uvr induced dna damage   as well as reduced efficiency of immune - surveillance and dna repair mechanisms with aging . in our study , higher frequency among rural inhabitants was seen when compared to urban residents .
this can be explained on the basis of more outdoor activities ( as agriculture is the main occupation ) , changes in clothing preferences , illiteracy , and infrequent use of sunscreens .
the rural patients regard initial lesions of bcc as a minor cosmetic problem with insignificant impact on health and seek medical advice only when lesions become symptomatic or disfiguring .
a study done in punjab regarding cancer found that tap water contains high content of arsenic , chromium , iron , and mercury , whereas ground water has abundance of arsenic , chromium , nickel , and iron .
tseng et al . found a dose - dependent relation between arsenic levels in drinking water and the prevalence of skin cancers .
thus , exposure to harmful metals and pesticides may also add to the risk of skin cancers , but further clinical and research studies are needed to confirm their role in the pathogenesis of bcc and to delineate underlying mechanisms .
occupations at risk of bcc that are highlighted in our study include agricultural workers and housekeepers .
immunocompromised patients like hiv positive patients or organ transplant recipients have a markedly increased risk of both typical and highly invasive nmsc .
interesting fact is that while the bcc / scc incidence ratio is approximately 4  :  1 in the general population , sccs become more prevalent in the transplant population with a bcc / scc ratio of approximately 1  :  2 .
some studies refute any relationship between smoking and risk of bcc , while boyd et al . found that bcc in young women is linked with past or current smoking .
smith and randle described an increased prevalence of bcc larger than 1  cm in diameter among the smokers .
other iatrogenic risk factors associated with bcc include treatment with psoralens and uva therapy and nbuvb for various ailments .
none of the patients in our study had received such treatments . in a retrospective ,
nation - wide cohort study of patients with psoriasis subjected to climatotherapy at the dead sea , it was found that the overall risk of cancer in patients treated at the dead sea was higher than that expected in the general population , owing to an excess risk of nonmelanoma skin cancer ( nmsc ) , with multiple lesions being more common and predilection for younger individuals . the most common location in our study was head and neck area ( 97.2% ) which is close to what was observed by malhotra et al . .
this pigmentation might be misleading as , clinically , bcc may be misdiagnosed as melanoma . although most bccs are slow - growing , relatively nonaggressive tumors , a minority have an aggressive behavior with local tissue destruction and , rarely , metastasis .
risk factors for development of metastatic bcc include large primary tumor ( > 2  cm ) , location in head and neck region , long standing lesion , multiple primary tumors and recurrences , prior radiation therapy , large tumor depth , invasion of perineural space and blood vessels , fair skin , male gender , and immunosuppression .
this study highlights a paradoxically increasing trend of bcc with female predilection and higher percentage of pigmented lesions in indians .
major contributory risk factors include intermittent rather than constant uv exposure , cultural and lifestyle changes , cosmetic indifference , possible role of arsenic and pesticides , improved clinical awareness , and diagnostic facilities .
the increasing cancer burden calls for the need of introduction of national screening program including mandatory annual skin examination by trained health professionals at the national level . since early detection and treatment of lesions
are crucial to decrease functional and cosmetic morbidity and costs , this study highlights the importance of improving awareness among general practitioners , public health workers , and general population .
the clinical and epidemiological data collected in this study would serve as a reference for future research and may be helpful in the development of preventive and educational strategies .
 
 objectives . 
 although the incidence of skin cancers in india ( part of south asia ) is low , the absolute number of cases may be significant due to large population . 
 the existing literature on bcc in india is scant . 
 so , this study was done focusing on its epidemiology , risk factors , and clinicopathological aspects . 
 methods . 
 a hospital based cross - sectional study was conducted in punjab , north india , from 2011 to 2013 . 
 history , examination and histopathological confirmation were done in all the patients visiting skin department with suspected lesions . results . 
 out of 36 confirmed cases , 63.9% were females with mean  sd age being 60.9  14.2 years . 
 mean duration of disease was 4.7 years . 
 though there was statistically significant higher sun exposure in males compared to females ( p value being 0.000 ) , bcc was commoner in females , explainable by intermittent sun exposure ( during household work in the open kitchens ) in women . 
 majority of patients ( 88.9% ) had a single lesion . 
 head and neck region was involved in 97.2% of cases , with nose being the commonest site ( 50% ) with nodular / noduloulcerative morphology in 77.8% of cases . 
 pigmentation was evident in 22.2% of cases clinically . 
 nodular variety was the commonest histopathological variant ( 77.8% ) . 
 conclusions . 
 this study highlights a paradoxically increasing trend of bcc with female preponderance , preferential involvement of nose , and higher percentage of pigmentation in indians . 
1. Introduction
2. Methods
3. Results
4. Discussion
5. Conclusions