| Domain | Key finding (with numbers) | Population/cohort | Study (first author year) | Publication date | URL/DOI | Evidence citation ID |
|---|---|---|---|---|---|---|
| Epidemiology | Estimated prevalence in SEER: **0.0011%**; incidence increased **4.03%/year (1973-1985)**, then declined **0.32%/year (1986-2015)** | **2,090** anal canal adenocarcinoma cases from SEER (1973-2015) | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000000, pqac-00000002) |
| Epidemiology | Mean age at diagnosis **68.12 ± 14.02 years**; **54.8% male**; presentation: **44.4% localized**, **25.8% regional**, **13.5% distant**, **6.7% in situ** | **2,090** SEER cases | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000000, pqac-00000002) |
| Survival | Overall survival rates at **1, 2, 3, 4, 5 years: 76.1%, 63.4%, 52.6%, 47.9%, 39.6%** | **2,090** SEER cases | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000002) |
| Survival | Surgery associated with markedly longer survival: **116.7 months vs 42.7 months** without surgery (**p < 0.01**) | **2,090** SEER cases | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000000) |
| Survival | Age >81 years associated with poorer outcome: mean survival **30.14 ± 1.84 months**; **HR 3.79** (95% CI 2.65-5.41) | **2,090** SEER cases | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000002) |
| Survival | Metastatic disease associated with ~**6-fold** higher mortality: **HR 6.02** (95% CI 4.55-7.99) | **2,090** SEER cases | Gogna 2020 | 2020-05-13 | https://doi.org/10.1155/2020/5139236 | (pqac-00000002) |
| Treatment | 3-year cause-specific survival by initial treatment: **63.9%** (RT+CTx), **35.7%** (RT or CTx), **77.7%** (surgery alone), **80.3%** (preop RT/CTx + surgery), **65.8%** (postop RT/CTx + surgery); **P < .001** | **393** stage I-III cases in SEER (2010-2016) | Park 2020 | 2020-09 | https://doi.org/10.1016/j.clcc.2020.04.001 | (pqac-00000003) |
| Treatment | Preoperative RT/CTx plus surgery associated with improved cause-specific survival on multivariable analysis (**P = .024**) | **393** stage I-III SEER cases | Park 2020 | 2020-09 | https://doi.org/10.1016/j.clcc.2020.04.001 | (pqac-00000003) |
| Molecular subtype | Two subtypes identified: anal gland/transitional-type **26/74 (35.1%)** vs colorectal-type **48/74 (64.9%)** | **74** primary anal canal adenocarcinomas | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000012) |
| HPV/MMR | HPV16/18 detected only in anal gland/transitional tumors: **11/26 (42.3%)**; p16 strong/diffuse staining in **12/26 (46.2%)** Krt7-positive tumors | **74** tumors; subtype analysis within **26** gland/transitional tumors | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000011, pqac-00000012) |
| HPV/MMR | Among HPV-infected tumors, **5/11 (45.5%)** showed patches of p16 negativity; MSI-high/MMR-deficient phenotype observed in only **1/74 (1.4%)** tumors | **74** tumors | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000008, pqac-00000011) |
| Mutations | EGFR protein detected in **64/74 (86.5%)** cancers | **74** tumors | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000008, pqac-00000010) |
| Mutations | Mutation frequencies: **KRAS 47.1%**, **NRAS 5.9%**, **PIK3CA 7.6%**, **PTEN 2.9%**, **BRAF 1.5%**; **EGFR, HER2, KIT, PDGFRA, DDR2 mutations absent** | **74** tumors | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000010, pqac-00000013) |
| Immune microenvironment | Anal gland/transitional-type tumors showed higher PD-1/PD-L1 expression and more prominent T-cell infiltration than colorectal-type counterparts | **74** tumors | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000008, pqac-00000009, pqac-00000014) |
| Prognosis by subtype | In survival subset, **65/74 (87.8%)** evaluable; **9/74 (12.2%)** metastatic at diagnosis; recurrence **10/24 (41.7%)** in anal gland/transitional vs **13/41 (31.7%)** in colorectal-type; 5-year DFS **33.1% vs 52.6%** and 5-year OS **27.8% vs 50.4%** | **65** evaluable for OS/DFS within a **74**-case cohort | Herfs 2018 | 2018 | Not available in retrieved metadata | (pqac-00000010) |
| Comparative prognosis | Anal adenocarcinoma represented **5%-10%** of anal canal malignancies and had worse prognosis than rectal adenocarcinoma and anal squamous carcinoma in comparative SEER analysis | SEER comparative cohort; anal adenocarcinoma subset noted as **1,660** in excerpted review | Tsay 2021 | 2021-07 | https://doi.org/10.1136/bmjgast-2021-000661 | (pqac-00000001, pqac-00000004) |


*Table: This table compiles key numeric findings for anal canal adenocarcinoma across epidemiology, survival, molecular subtype, HPV/MMR status, mutations, and treatment outcomes. It is useful as a quick-reference evidence map for populating structured disease knowledge base fields.*