Q (sonnet): In the TCGA PanCancer Atlas endometrial cancer study, what percentage of patients have co-occurring oncogenic mutations in both KRAS and NRAS? ▶ read_guide { "uri": "cbioportal://statistical-tests-guide" } ▶ read_guide { "uri": "cbioportal://mutation-frequency-guide" } ◀ result Statistical Test Selection Guide ================================ Purpose ------- This guide ensures the correct statistical test is selected before performing any group comparison, matching cBioPortal's own Group Comparison defaults. HARD RULES — NEVER FABRICATE A STATISTIC ---------------------------------------- ClickHouse cannot run statistical tests. The agent therefore must NEVER produce a derived statistic that is not a literal column value from a SQL result. Specifically: 1. **Never invent a p-value.** Not "p < 0.001", not "p ≈ 0.05", not any p-value. If the user asks "what is the p-value?", the answer is *"I can't compute that — here is the 2x2 contingency table (or group statistics). Run it in cBioPortal's Group Comparison tab, in R with `fisher.test(...)` / `wilcox.test(...)`, or in Python with `scipy.stats.fisher_exact(...)` / `mannwhitneyu(...)`."* 2. **Never claim mutual exclusivity (or co-occurrence) from a contingency table alone.** A 2x2 table is not a test. The shape "altered/not altered × group A/group B" needs Fisher's exact + a defined direction (odds ratio < 1 with significant p). Without that test, the agent presents the table and stops. Descriptive phrasing is also a claim: "largely/mostly mutually exclusive", "rarely co-occur", "tend to co-occur" are forbidden without the test — point to cBioPortal's Mutual Exclusivity tab instead. 3. **Never report a "median" that came from `AVG(...)` or any non-median aggregate.** "Median" and "mean" are different statistics; for skewed clinical distributions (especially survival) they differ substantially. Use ClickHouse's `quantile(0.5)(...)` for actual median, and label arithmetic averages as "mean", never "median". 4. **Never report a hazard ratio, odds ratio, risk ratio, or relative risk** that wasn't computed by an external tool. These require regression / model fitting that ClickHouse does not do. 5. **Never report median overall survival from `AVG(OS_MONTHS)` or even `quantile(0.5)(OS_MONTHS)`.** Median OS requires Kaplan-Meier estimation, which handles censoring (`OS_STATUS = 0:LIVING` means the event hasn't happened yet). Naive medians/means over `OS_MONTHS` ignore censoring and are systematically wrong. The correct handoff: return the raw `(OS_MONTHS, OS_STATUS)` pairs (or descriptive counts: N events, N censored, follow-up range) and tell the user to run KM in R (`survival::survfit`) or Python (`lifelines.KaplanMeierFitter`), or use cBioPortal's Survival comparison. If asked to do any of (1)–(5), respond with the appropriate handoff template from the "Approved Response Templates" section below — do not produce the number. Ambiguous-Term Clarification (before any analysis) -------------------------------------------------- If the user's question uses an ambiguous term, ask before computing anything. Examples: - **"aggressive"** → could mean shorter overall survival, higher metastasis rate, higher grade/stage, higher TMB, or specific molecular features. Ask which definit … (9984 more chars) ◀ result # Mutation Frequency Analysis Guide ## IMPORTANT: Reporting Mutation Frequencies - **ALWAYS report frequencies as percentages**, not raw counts: `frequency = (altered_samples / total_profiled_samples) × 100` - For quick frequency lookups, **prefer the TCGA Pan-Cancer Atlas study first**, then offer to expand to other studies - When reporting across multiple studies, show **ranges** (e.g., "TP53 is mutated in 30–60% of samples") rather than a single average - **NEVER** sum mutation events across studies to compute an aggregate frequency — this can exceed 100% due to double-counting - Warn users that samples may overlap across cohorts (e.g., MSK studies may share patients) - **Choose and state the counting unit**: use patient-level frequencies for prevalence/rate questions unless the user explicitly asks for samples; use sample-level frequencies when the user asks about samples. - **For "across cancer types" questions**, jump to the [Cross-Cancer-Type Mutation Frequency](#cross-cancer-type-mutation-frequency) section below — there is one correct recipe and several common wrong ones. ## Counting Unit: Samples vs Patients Before answering any mutation count or frequency question, decide whether the unit is samples or patients and state that choice in the answer. | User wording | Counting unit | |--------------|---------------| | "prevalence", "rate", "fraction of patients", "patients with", "how common is" | Patient-level: `COUNT(DISTINCT patient_unique_id)` | | "samples", "specimens", "biopsies", sample-level cohort composition | Sample-level: `COUNT(DISTINCT sample_unique_id)` | | Ambiguous | Ask, or default to patient-level for prevalence/rate language and say so | ### Cross-study sample-count caveat When an answer touches more than one study and reports a sample count, prepend a one-line caveat: > Sample IDs are unique within cBioPortal study prefixes, not guaranteed biological-sample identifiers across studies; overlapping cohorts can count the same patient/sample more than once. Prefer one of these safer approaches: - Use a shipped `cancer_study_query_preferences` cohort such as `pan_cancer_tcga` or `all_studies_non_redundant`. - Restrict to one named study. - Aggregate by `patient_unique_id` when the biological question is patient prevalence. ## STOP rule: a frequency above 100% means your query is wrong If your query returns a frequency over 100%, **do not try to debug or explain the data inconsistency to the user**. The cause is always one of these query bugs: - Summing mutation events instead of `COUNT(DISTINCT sample_unique_id)` for the numerator - Using a study-wide sample count as the denominator instead of the gene-specific profiled count - Cross-study aggregation where the same biological sample appears under multiple `sample_unique_id` values (e.g., MSK-IMPACT and MSK-CHORD share patients) - **Joining the profiled CTE through `gene_panel` / `gene_panel_list` without a WES branch.** `gene_panel_id = 'WES'` is *not* a row in … (36467 more chars) ▶ clickhouse_run_select_query { "query": " SELECT driver_filter, count() AS mutations FROM genomic_event_derived WHERE cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' AND variant_type = 'mutation' AND hugo_gene_symbol IN ('KRAS','NRAS') GROUP BY driver_filter " } ◀ result {"rows":[{"mutations":123}]} ▶ clickhouse_run_select_query { "query": " WITH profiled AS ( SELECT DISTINCT c.patient_unique_id FROM sample_to_gene_panel_derived s JOIN clinical_data_derived c USING (sample_unique_id) WHERE s.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' AND s.alteration_type = 'MUTATION_EXTENDED' AND c.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' ), mut AS ( SELECT DISTINCT c.patient_unique_id, g.hugo_gene_symbol FROM genomic_event_derived g JOIN clinical_data_derived c USING (sample_unique_id) WHERE g.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' AND g.variant_type = 'mutation' AND g.mutation_status != 'UNCALLED' AND g.off_panel = 0 AND g.hugo_gene_symbol IN ('KRAS','NRAS') ) SELECT (SELECT count() FROM profiled) AS profiled_patients, uniqExactIf(patient_unique_id, hugo_gene_symbol='KRAS') AS kras_mut, uniqExactIf(patient_unique_id, hugo_gene_symbol='NRAS') AS nras_mut, (SELECT count() FROM ( SELECT patient_unique_id FROM mut GROUP BY patient_unique_id HAVING count(DISTINCT hugo_gene_symbol) = 2 )) AS both_mut FROM mut " } ◀ result {"error_message":"Query execution failed: HTTPDriver for https://dl96orhu96.us-east-1.aws.clickhouse.cloud:8443 received ClickHouse error code 47\n Code: 47. DB::Exception: Unknown expression or function identifier `patient_unique_id` in scope WITH profiled AS (SELECT DISTINCT c.patient_unique_id FROM sample_to_gene_panel_derived AS s INNER JOIN clinical_data_derived AS c USING (sample_unique_id) WHERE (s.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018') AND (s.alteration_type = 'MUTATION_EXTENDED') AND (c.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018')), mut AS (SELECT DISTINCT c.patient_unique_id, g.hugo_gene_symbol FROM genomic_event_derived AS g INNER JOIN clinical_data_derived AS c USING (sample_unique_id) WHERE (g.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018') AND (g.variant_type = 'mutation') AND (g.mutation_status != 'UNCALLED') AND (g.off_panel = 0) AND (g.hugo_gene_symbol IN ('KRAS', 'NRAS'))) SELECT (SELECT count() FROM profiled) AS profiled_patients, uniqExactIf(patient_unique_id, hugo_gene_symbol = 'KRAS') AS kras_mut, uniqExactIf(patient_unique_id, hugo_gene_symbol = 'NRAS') AS nras_mut, (SELECT count() FROM (SELECT patient_unique_id FROM mut GROUP BY patient_unique_id HAVING countDistinct(hugo_gene_symbol) = 2)) AS both_mut FROM mut. (UNKNOWN_IDENTIFIER) (version 26.4.1.2359 (official build))\n"} ▶ clickhouse_run_select_query { "query": " SELECT count(DISTINCT c.patient_unique_id) AS profiled_patients FROM sample_to_gene_panel_derived s JOIN clinical_data_derived c USING (sample_unique_id) WHERE s.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' AND s.alteration_type = 'MUTATION_EXTENDED' AND c.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' " } ◀ result {"rows":[{"profiled_patients":517}]} ▶ clickhouse_run_select_query { "query": " WITH mut AS ( SELECT DISTINCT c.patient_unique_id AS pid, g.hugo_gene_symbol AS gene FROM genomic_event_derived g JOIN clinical_data_derived c USING (sample_unique_id) WHERE g.cancer_study_identifier = 'ucec_tcga_pan_can_atlas_2018' AND g.variant_type = 'mutation' AND g.mutation_status != 'UNCALLED' AND g.off_panel = 0 AND g.hugo_gene_symbol IN ('KRAS','NRAS') ) SELECT uniqExactIf(pid, gene='KRAS') AS kras_mut_patients, uniqExactIf(pid, gene='NRAS') AS nras_mut_patients, (SELECT count() FROM (SELECT pid FROM mut GROUP BY pid HAVING count(DISTINCT gene) = 2)) AS both_mut_patients FROM mut " } ◀ result {"rows":[{"kras_mut_patients":99,"nras_mut_patients":21,"both_mut_patients":4}]} ▶ resolve_and_route { "studyIds": [ "ucec_tcga_pan_can_atlas_2018" ] } ◀ result {"success":true,"message":"Found 1 study. Use the metadata to call the appropriate navigation tool(s).","data":{"totalCount":1,"studiesWithMetadata":[{"studyId":"ucec_tcga_pan_can_atlas_2018","name":"Uterine Corpus Endometrial Carcinoma (TCGA, PanCancer Atlas)","sampleCount":529,"studyViewUrl":"https://www.cbioportal.org/study?id=ucec_tcga_pan_can_atlas_2018","metadata":{"clinicalAttributeIds":["AGE","AJCC_PATHOLOGIC_TUMOR_STAGE","AJCC_STAGING_EDITION","ANEUPLOIDY_SCORE","BUFFA_HYPOXIA_SCORE","CANCER_TYPE","CANCER_TYPE_ACRONYM","CANCER_TYPE_DETAILED","DAYS_LAST_FOLLOWUP","DAYS_TO_BIRTH","DAYS_TO_INITIAL_PATHOLOGIC_DIAGNOSIS","DFS_MONTHS","DFS_STATUS","DSS_MONTHS","DSS_STATUS","ETHNICITY","FORM_COMPLETION_DATE","FRACTION_GENOME_ALTERED","GENETIC_ANCESTRY_LABEL","GRADE","HISTORY_NEOADJUVANT_TRTYN","ICD_10","ICD_O_3_HISTOLOGY","ICD_O_3_SITE","INFORMED_CONSENT_VERIFIED","IN_PANCANPATHWAYS_FREEZE","MSI_SCORE_MANTIS","MSI_SENSOR_SCORE","MUTATION_COUNT","NEW_TUMOR_EVENT_AFTER_INITIAL_TREATMENT","ONCOTREE_CODE","OS_MONTHS","OS_STATUS","OTHER_PATIENT_ID","PATH_M_STAGE","PATH_N_STAGE","PATH_T_STAGE","PERSON_NEOPLASM_CANCER_STATUS","PFS_MONTHS","PFS_STATUS","PRIMARY_LYMPH_NODE_PRESENTATION_ASSESSMENT","PRIOR_DX","RACE","RADIATION_THERAPY","RAGNUM_HYPOXIA_SCORE","SAMPLE_COUNT","SAMPLE_TYPE","SEX","SOMATIC_STATUS","SUBTYPE","TBL_SCORE","TISSUE_PROSPECTIVE_COLLECTION_INDICATOR","TISSUE_RETROSPECTIVE_COLLECTION_INDICATOR","TISSUE_SOURCE_SITE","TISSUE_SOURCE_SITE_CODE","TMB_NONSYNONYMOUS","TUMOR_TISSUE_SITE","TUMOR_TYPE","WEIGHT","WINTER_HYPOXIA_SCORE"],"molecularProfileIds":["ucec_tcga_pan_can_atlas_2018_gistic","ucec_tcga_pan_can_atlas_2018_log2CNA","ucec_tcga_pan_can_atlas_2018_mutations","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_Zscores","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_all_sample_Zscores","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_all_sample_ref_normal_Zscores","ucec_tcga_pan_can_atlas_2018_rppa","ucec_tcga_pan_can_atlas_2018_rppa_Zscores","ucec_tcga_pan_can_atlas_2018_structural_variants"],"genericAssayProfiles":["ucec_tcga_pan_can_atlas_2018_armlevel_cna","ucec_tcga_pan_can_atlas_2018_genetic_ancestry","ucec_tcga_pan_can_atlas_2018_methylation_hm27_hm450_merge","ucec_tcga_pan_can_atlas_2018_methylation_hm450"],"heatmapProfileIds":["ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_Zscores","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_all_sample_Zscores","ucec_tcga_pan_can_atlas_2018_rna_seq_v2_mrna_median_all_sample_ref_normal_Zscores","ucec_tcga_pan_can_atlas_2018_rppa_Zscores"],"availableComparisonTabs":["overlap","clinical","survival","alterations","mutations","mrna","protein","generic_assay_armlevel_cna","generic_assay_genetic_ancestry","generic_assay_methylation"]}}]}} ▶ navigate_to_results_view { "studyIds": [ "ucec_tcga_pan_can_atlas_2018" ], "genes": [ "KRAS: MUT_DRIVER", "NRAS: MUT_DRIVER" ], "tab": "oncoprint" } ◀ result {"success":true,"message":"Navigating to https://www.cbioportal.org/results/oncoprint?cancer_study_list=ucec_tcga_pan_can_atlas_2018&gene_list=KRAS%3A+MUT_DRIVER%0ANRAS%3A+MUT_DRIVER&case_set_id=ucec_tcga_pan_can_atlas_2018_all","url":"https://www.cbioportal.org/results/oncoprint?cancer_study_list=ucec_tcga_pan_can_atlas_2018&gene_list=KRAS%3A+MUT_DRIVER%0ANRAS%3A+MUT_DRIVER&case_set_id=ucec_tcga_pan_can_atlas_2018_all","data":{"studyIds":["ucec_tcga_pan_can_atlas_2018"],"studies":[{"studyId":"ucec_tcga_pan_can_atlas_2018","name":"Uterine Corpus Endometrial Carcinoma (TCGA, PanCancer Atlas)","sampleCount":529}],"genes":["KRAS","NRAS"],"caseSetId":"ucec_tcga_pan_can_atlas_2018_all","pageDescription":"Visual summary of alterations in queried genes across samples."}} ═ answer (success) ## Important caveat on "oncogenic" This study's underlying database has **no driver/pathogenicity annotation stored** for KRAS or NRAS mutations (the `driver_filter` field, which flags a study's own curated driver calls, is empty for all 123 KRAS/NRAS mutation records in this cohort). I therefore cannot report a true "oncogenic-only" percentage directly from the database — the figures below reflect **all non-synonymous mutations**, not an OncoKB-filtered oncogenic subset. To get the OncoKB-oncogenic-restricted number, use the OncoPrint link below, which applies the `MUT_DRIVER` filter (OncoKB + hotspot annotation computed live by the cBioPortal web app). ## Co-mutation counts (all KRAS/NRAS mutations, patient-level) **Study:** [Uterine Corpus Endometrial Carcinoma (TCGA, PanCancer Atlas)](https://www.cbioportal.org/study?id=ucec_tcga_pan_can_atlas_2018) — 517 patients profiled for mutations (whole-exome) | | Patients | % of profiled | |---|---|---| | KRAS mutated | 99 | 19.1% | | NRAS mutated | 21 | 4.1% | | **Both KRAS and NRAS mutated** | **4** | **0.8%** | So **0.8% (4 of 517 profiled patients)** carry mutations in both KRAS and NRAS in this cohort — but again, that count includes all mutation types, not confirmed oncogenic/driver variants specifically. I cannot state whether this co-occurrence is more or less frequent than expected by chance — that requires Fisher's exact test / mutual exclusivity analysis, which I have not run here. [View KRAS/NRAS driver-mutation OncoPrint](https://www.cbioportal.org/results/oncoprint?cancer_study_list=ucec_tcga_pan_can_atlas_2018&gene_list=KRAS%3A+MUT_DRIVER%0ANRAS%3A+MUT_DRIVER&case_set_id=ucec_tcga_pan_can_atlas_2018_all) — this applies cBioPortal's live OncoKB/hotspot driver filter (`MUT_DRIVER`), which is the correct way to isolate oncogenic-only calls; use the Mutual Exclusivity tab there for a formal co-occurrence test.