What are the incidence statistics of colorectal cancer in the Philippines, and is it more common in males or females?

Colorectal Cancer Statistics in the Philippines: Sex Distribution

Colorectal cancer in the Philippines affects males and females nearly equally, with an almost 1:1 male-to-female ratio, though males show a slightly higher incidence overall. 1

Sex-Specific Incidence Patterns

Overall Distribution

• The male-to-female ratio for colorectal cancer in the Philippines is approximately 1:1, based on surgical pathology data from 1,277 Filipino patients 1
• This near-equal distribution contrasts with many Asian countries where male predominance is more pronounced 2

Site-Specific Sex Differences

• Rectal cancers are more frequent in males 1
• Right colon cancers are more common in females 1
• The Philippines exhibits a markedly higher proportion of rectal cancers (approximately 50% of all colorectal cancer cases), which differs substantially from Western populations where the colon-to-rectum ratio is typically 2:1 3

Epidemiologic Context in the Philippines

Age and Presentation Characteristics

• Filipino patients are diagnosed at a mean age of approximately 55 years, considerably younger than the median age of 70 years in Western populations 3
• Patients 40 years of age and younger comprise 17% of all cases, indicating a substantial burden of early-onset disease 1
• The majority of patients present in their sixth and seventh decades of life 1

Disease Distribution by Anatomic Site

• Rectum: 49.8% (most common site) 1
• Left colon: 27.9% 1
• Right colon: 21.4% 1

Stage at Presentation

• 44% of patients have localized disease at operation 1
• 54% present with regional disease 1
• 2% have disseminated disease at presentation 1
• Late-stage diagnosis is largely responsible for lower survival rates compared to Filipino-Americans and Whites in the USA 4

Regional Trends and Incidence Patterns

Rising Incidence in the Philippines

• Colorectal cancer showed a steady increase in incidence from 1980-2002 in Metro Manila and Rizal province 4
• Among females, colorectal cancer became equally common as cervical cancer (the second most common cancer) by 2002 4
• Among males, colorectal cancer showed rising trends and became more common than liver cancer 4

Broader Asian Context

• Colorectal cancer is one of the most common cancers in Asia in both males and females, though the Philippines has lower incidence rates compared to high-incidence Asian countries like Japan, Korea, Singapore, and Hong Kong 2
• In countries like India, Philippines, and Vietnam, there remains a gap in CRC incidence compared to Western nations 2

Clinical Implications

Unique Filipino Characteristics

• The higher proportion of rectal cancers and younger age at diagnosis suggest a potentially different tumor development pathway in this population 1
• Associated predisposing conditions include polyps (4.7%), schistosomiasis (3%), and tuberculosis (1.5%) 1
• Current Western screening guidelines may not be appropriate for Filipinos given these unique clinicopathologic features 1

Screening Awareness

• Knowledge scores regarding colorectal cancer prognosis and screening utility are modest among Filipinos (6.3/12 and 8.4/20, respectively) 5
• Despite modest knowledge, 86.1% of Filipinos are willing to participate in government-initiated screening programs 5
• Household income and educational attainment significantly correlate with knowledge scores and perceived benefits of screening 5