Q (sonnet): What percentage of patients in the MSK-CHORD Study have at least one TP53 mutation? ▶ read_guide { "uri": "cbioportal://mutation-frequency-guide" } ▶ list_studies { "search": "MSK CHORD" } ◀ 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) ◀ result {"result":[{"cancer_study_identifier":"msk_chord_2024","name":"MSK-CHORD (MSK, Nature 2024)","type_of_cancer_id":"mixed","sample_count":25040,"has_guide":true,"url":"https://www.cbioportal.org/study/summary?id=msk_chord_2024"}]} ▶ clickhouse_run_select_query { "query": " WITH profiled_patients AS ( SELECT DISTINCT c.patient_unique_id FROM sample_to_gene_panel_derived s JOIN clinical_data_derived c ON s.sample_unique_id = c.sample_unique_id AND c.cancer_study_identifier = 'msk_chord_2024' WHERE s.cancer_study_identifier = 'msk_chord_2024' AND s.alteration_type = 'MUTATION_EXTENDED' ), altered_patients AS ( SELECT DISTINCT c.patient_unique_id FROM genomic_event_derived g JOIN clinical_data_derived c ON g.sample_unique_id = c.sample_unique_id AND c.cancer_study_identifier = 'msk_chord_2024' WHERE g.cancer_study_identifier = 'msk_chord_2024' AND g.variant_type = 'mutation' AND g.mutation_status != 'UNCALLED' AND g.hugo_gene_symbol = 'TP53' AND g.off_panel = 0 ) SELECT (SELECT count() FROM profiled_patients) AS profiled_patients, (SELECT count() FROM altered_patients WHERE patient_unique_id IN (SELECT patient_unique_id FROM profiled_patients)) AS altered_patients, round((SELECT count() FROM altered_patients WHERE patient_unique_id IN (SELECT patient_unique_id FROM profiled_patients)) * 100.0 / (SELECT count() FROM profiled_patients), 1) AS frequency_pct " } ◀ 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 table expression identifier `patient_unique_id` in scope (SELECT count() FROM altered_patients WHERE patient_unique_id IN (SELECT patient_unique_id FROM profiled_patients)) AS altered_patients. (UNKNOWN_IDENTIFIER) (version 26.4.1.2359 (official build))\n"} ▶ clickhouse_run_select_query { "query": " WITH profiled_patients AS ( SELECT DISTINCT c.patient_unique_id AS patient_unique_id FROM sample_to_gene_panel_derived s JOIN clinical_data_derived c ON s.sample_unique_id = c.sample_unique_id AND c.cancer_study_identifier = 'msk_chord_2024' WHERE s.cancer_study_identifier = 'msk_chord_2024' AND s.alteration_type = 'MUTATION_EXTENDED' ), altered_patients AS ( SELECT DISTINCT c.patient_unique_id AS patient_unique_id FROM genomic_event_derived g JOIN clinical_data_derived c ON g.sample_unique_id = c.sample_unique_id AND c.cancer_study_identifier = 'msk_chord_2024' WHERE g.cancer_study_identifier = 'msk_chord_2024' AND g.variant_type = 'mutation' AND g.mutation_status != 'UNCALLED' AND g.hugo_gene_symbol = 'TP53' AND g.off_panel = 0 ) SELECT (SELECT count() FROM profiled_patients) AS profiled_n, count() AS altered_n, round(count() * 100.0 / (SELECT count() FROM profiled_patients), 1) AS frequency_pct FROM altered_patients WHERE patient_unique_id IN (SELECT patient_unique_id FROM profiled_patients) " } ◀ result {"rows":[{"profiled_n":24950,"altered_n":13105,"frequency_pct":52.5}]} ▶ resolve_and_route { "studyIds": [ "msk_chord_2024" ] } ◀ result {"success":true,"message":"Found 1 study. Use the metadata to call the appropriate navigation tool(s).","data":{"totalCount":1,"studiesWithMetadata":[{"studyId":"msk_chord_2024","name":"MSK-CHORD (MSK, Nature 2024)","sampleCount":25040,"studyViewUrl":"https://www.cbioportal.org/study?id=msk_chord_2024","metadata":{"clinicalAttributeIds":["ADRENAL_GLANDS","BONE","CANCER_TYPE","CANCER_TYPE_DETAILED","CLINICAL_GROUP","CLINICAL_SUMMARY","CNS_BRAIN","CURRENT_AGE_DEID","DIAGNOSIS_DESCRIPTION","ETHNICITY","FRACTION_GENOME_ALTERED","GENDER","GENE_PANEL","GLEASON_FIRST_REPORTED","GLEASON_HIGHEST_REPORTED","GLEASON_SAMPLE_LEVEL","HER2","HISTORY_OF_PDL1","HR","ICD_O_HISTOLOGY_DESCRIPTION","INTRA_ABDOMINAL","LIVER","LUNG","LYMPH_NODES","METASTATIC_SITE","MSI_COMMENT","MSI_SCORE","MSI_TYPE","MUTATION_COUNT","NUM_ICDO_DX","ONCOTREE_CODE","OS_MONTHS","OS_STATUS","OTHER","PATHOLOGICAL_GROUP","PDL1_POSITIVE","PLEURA","PRIMARY_SITE","PRIOR_MED_TO_MSK","RACE","REPRODUCTIVE_ORGANS","SAMPLE_CLASS","SAMPLE_COUNT","SAMPLE_COVERAGE","SAMPLE_TYPE","SMOKING_PREDICTIONS_3_CLASSES","SOMATIC_STATUS","STAGE_HIGHEST_RECORDED","TMB_NONSYNONYMOUS","TUMOR_PURITY"],"molecularProfileIds":["msk_chord_2024_cna","msk_chord_2024_mutations","msk_chord_2024_structural_variants"],"availableComparisonTabs":["overlap","clinical","survival","alterations","mutations"]}}]}} ▶ navigate_to_results_view { "studyIds": [ "msk_chord_2024" ], "genes": [ "TP53: MUT" ], "tab": "oncoprint" } ◀ result {"success":true,"message":"Navigating to https://www.cbioportal.org/results/oncoprint?cancer_study_list=msk_chord_2024&gene_list=TP53%3A+MUT&case_set_id=msk_chord_2024_all","url":"https://www.cbioportal.org/results/oncoprint?cancer_study_list=msk_chord_2024&gene_list=TP53%3A+MUT&case_set_id=msk_chord_2024_all","data":{"studyIds":["msk_chord_2024"],"studies":[{"studyId":"msk_chord_2024","name":"MSK-CHORD (MSK, Nature 2024)","sampleCount":25040}],"genes":["TP53"],"caseSetId":"msk_chord_2024_all","pageDescription":"Visual summary of alterations in queried genes across samples."}} ═ answer (success) ## TP53 Mutation Prevalence in MSK-CHORD In the **MSK-CHORD** study (MSK, Nature 2024), **13,105 of 24,950 patients profiled for mutations (52.5%)** carry at least one TP53 mutation. - Counting unit: patients (not samples), restricted to on-panel mutation calls (excluding uncalled variants). - Denominator: patients with at least one sample profiled for mutation status in this study (24,950 of the study's total patient population). Note: MSK-CHORD is a pan-cancer cohort spanning multiple tumor types, so this 52.5% figure is a pooled average across cancer types — TP53 mutation rates vary substantially by tumor type (e.g., much higher in lung and ovarian cancers, lower in others). Let me know if you'd like the breakdown by cancer type. [View TP53 mutations in MSK-CHORD (OncoPrint)](https://www.cbioportal.org/results/oncoprint?cancer_study_list=msk_chord_2024&gene_list=TP53%3A+MUT&case_set_id=msk_chord_2024_all)