This retrospective, province-wide, multicentre observational study quantified cancer counts and calculated age-standardised incidence rates (ASIRs) per 100,000 population in Khyber Pakhtunkhwa (KP), Pakistan, for the period 1 January 2020 to 31 December 2023. The primary objectives were to determine cancer counts, proportions and ASIRs for children (0–14 years), adolescents/young adults (15–19 years) and adults (≥20 years) among KP residents and to compare these incidence rates with published data from Lahore, Karachi and nearby regions (Kabul, Iran).
Data were centrally collated at the Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC) hospital information system. The primary contributing facilities were SKMCH&RC and Pakistan Atomic Energy Commission (PAEC) hospitals, which together accounted for 88.9% of the reported cases; Chughtai Lab contributed 10.1%. A broader network of collection centres and collaborating hospitals across Pakistan supplied additional records. The study used existing registry infrastructure and a centralised database to identify new cancer cases among KP inhabitants.
Case ascertainment combined active and passive approaches. Registry personnel conducted visits to collaborating centres and abstracted data from pathology reports and clinical records into the cancer registry module. Variables collected matched International Agency for Research on Cancer (IARC) recommendations (including demographics, tumour site and morphology, behaviour, and the most valid basis of diagnosis). Records were de-duplicated using combinations of identifiers (name, age, father’s name, site, phone, address). Tumours were coded using ICD-O, Third Edition, and standard multiple-primary rules were applied.
Population denominators were estimated using the latest census-derived annual growth rate (2.38%), yielding an average annual KP person-years at risk of 39,479,405 (approximately 20 million males and 19.46 million females). ASIRs were calculated per 100,000 population using the Segi world standard population and computed with Microsoft Excel 2019. ASIRs are presented throughout per 100,000 population.
Between 2020 and 2023, 57,852 new cancer cases among KP residents were reported. Adults (≥20 years) constituted 90.9% of cases, children 6.6% and adolescents 2.6%. Females accounted for 51.6% and males 48.4% of the cohort. The mean age at diagnosis was 49.75 years (SD ±19.63; range 0.1–120 years).
The five most common cancers overall were: breast cancer (16.3%), non-Hodgkin lymphoma (NHL) (6.9%), colorectal/anal cancer (6.4%), skin cancers including melanoma and non-melanoma (5.6%), and urinary bladder cancer (4.6%).
Children (0–14 years)
Girls: 1,403 tumours registered. Leading diagnoses were lymphoid leukaemia (18.1%; ASIR 0.76), nervous system/brain tumours (12.3%; ASIR 0.51), NHL (11.5%; ASIR 0.48), bone tumours (8.8%; ASIR 0.36) and Hodgkin’s lymphoma (8.3%; ASIR 0.33).
Boys: 2,402 tumours registered. Dominant diagnoses were lymphoid leukaemia (20.6%; ASIR 1.4), Hodgkin’s lymphoma (16.4%; ASIR 1.0), NHL (14.6%; ASIR 0.93), nervous system/brain tumours (9.4%; ASIR 0.59) and connective/soft tissue tumours (6.5%; ASIR 0.43).
Adolescents (15–19 years)
Females (n=647): ovarian tumours (10.0%; ASIR 0.79), bone tumours (9.7%; ASIR 0.77), nervous system/brain (9.3%; ASIR 0.73), connective/soft tissue (9.1%; ASIR 0.72) and NHL (8.3%; ASIR 0.67).
Males (n=835): bone tumours (14.4%; ASIR 1.4), NHL (14.1%; ASIR 1.4), Hodgkin’s lymphoma (11.0%; ASIR 1.1), nervous system/brain (9.3%; ASIR 0.90) and connective/soft tissue tumours (8.9%; ASIR 0.87).
Adults (≥20 years)
Females: 27,828 tumours. Breast cancer was the most frequent (33.2%; ASIR 32.6), followed by ovarian (6.1%; ASIR 6.4), skin (5.2%; ASIR 6.1), colorectal/anal (5.0%; ASIR 5.1) and NHL (4.4%; ASIR 4.7).
Males: 24,737 tumours. Leading sites were prostate (9.2%; ASIR 9.1), colorectal/anal (8.8%; ASIR 7.6), bladder (8.5%; ASIR 8.2), NHL (8.4%; ASIR 7.4) and skin cancers (6.9%; ASIR 6.5).
Population-level ASIR summaries reported pre-adolescent ASIRs of 4.2 in girls and 6.6 in boys; adolescent ASIRs of 7.9 in females and 9.7 in males; and adult ASIRs of 103.5 in females and 90.1 in males.
Published ASIRs from Lahore and Karachi were extracted for comparative analysis, and aggregate published data from Kabul and Iran were used for regional comparison. Common patterns included elevated childhood leukaemia ASIRs in KP and Lahore and very high female breast ASIR in Karachi (reported as 177.8). Karachi also reported higher paediatric bone tumour ASIRs than KP. Differences across regions were noted, especially in the ranking of leading male cancers (e.g., stomach cancer ranked highly in Kabul and Iran whereas bladder cancer and NHL were prominent in KP). The authors note that methodological differences across registries and study periods may affect direct comparisons.
Strengths include province-wide, multicentre coverage and comparison with other regional registries. Limitations reported by the authors include uncertainty about completeness of reporting, insufficient data on diagnostic basis, stage, treatments and mortality, and potential biases when comparing registry data across regions due to methodological differences. The collated dataset is not publicly available but can be requested from the corresponding author under reasonable request conditions.
The study documents the burden and pattern of cancer in KP, highlighting prominent sites by age and sex—particularly the high burden of breast cancer in adult females and haematologic malignancies in children and adolescents. These findings provide baseline incidence estimates to inform planning for cancer prevention, early detection, diagnostic capacity and treatment infrastructure within the province and to support future comparative epidemiologic analyses.