Q (sonnet): show me all KRAS mutations in colorectal cancer that are not at position 12 ▶ read_guide { "uri": "cbioportal://mutation-frequency-guide" } ◀ 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) ▶ read_guide { "uri": "cbioportal://sample-filtering-guide" } ▶ search_oncotree { "search_term": "colorectal" } ◀ result # Sample and Study Filtering Guide ## Overview Proper filtering is essential for meaningful cBioPortal analysis. This guide covers filtering by studies, sample types, and other criteria. ## Study-Level Filtering ### 1. Always Filter by Study Every query should specify a study to ensure consistent results: ```sql -- Always include study filtering SELECT * FROM your_table WHERE cancer_study_identifier = 'your_study_id' -- Additional filters... ``` ### 2. Find Available Studies ```sql -- Discover available studies SELECT cancer_study_identifier, name, description, type_of_cancer_id FROM cancer_study ORDER BY cancer_study_identifier; ``` ### 3. Study Information ```sql -- Get detailed study information SELECT cs.cancer_study_identifier, cs.name as study_name, cs.description, cs.sample_count, COUNT(DISTINCT p.internal_id) as patient_count FROM cancer_study cs LEFT JOIN patient p ON cs.cancer_study_id = p.cancer_study_id WHERE cs.cancer_study_identifier = 'your_study_id' GROUP BY cs.cancer_study_identifier, cs.name, cs.description, cs.sample_count; ``` ### 4. Find Studies by Available Data Types Use this when the user asks *"which studies have mutation and copy-number data for X"*, *"studies with expression for Y"*, *"is there any imaging data"*, or any *"studies with Z data"* question. `cancer_study` has one precomputed sample count per data type — filter on them. No join and no schema exploration needed. These are the same counts as the portal's study list and its "Data type" filter. **Canonical query — studies with ALL requested data types for a cancer type:** ```sql SELECT cancer_study_identifier, name, sample_count, mutation_sample_count, cna_sample_count FROM cancer_study WHERE type_of_cancer_id = 'luad' -- ← OncoTree code from search_oncotree AND mutation_sample_count > 0 -- ← one condition per required data type AND cna_sample_count > 0 ORDER BY sample_count DESC; ``` **Data type → column** (a count of 0 means the study doesn't have that data): | Data type in the user's question | Column (portal "Data type" filter label) | |---|---| | samples in the study | `sample_count` | | mutation / mutations | `mutation_sample_count` ("Mutations") | | copy-number / CNA / amplification / deletion | `cna_sample_count` ("CNA") | | structural variant / fusion | `structural_variant_sample_count` | | RNA / mRNA / gene expression (any platform) | `mrna_expression_sample_count` — use this for "which studies have expression data" | | specifically the portal's "RNA-Seq" filter | `rna_seq_sample_count` ("RNA-Seq") — counts only the `_rna_seq_v2_mrna` list; 0 for many GDC and iAtlas studies that do have RNA-Seq | | specifically the portal's "RNA (microarray)" filter | `mrna_microarray_sample_count` ("RNA (microarray)") — counts only the `_mrna` list | | microRNA | `mirna_sample_count` ("miRNA") | | protein / RPPA | `rppa_sample_count` ("RPPA") | | mas … (7866 more chars) ◀ result {"result":[{"code":"COADREAD","name":"Colorectal Adenocarcinoma","score":60,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD"},{"code":"CAIS","name":"Colon Adenocarcinoma In Situ","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD > CAIS"},{"code":"CMC","name":"Medullary Carcinoma of the Colon","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > CMC"},{"code":"COAD","name":"Colon Adenocarcinoma","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD > COAD"},{"code":"MACR","name":"Mucinous Adenocarcinoma of the Colon and Rectum","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD > MACR"},{"code":"READ","name":"Rectal Adenocarcinoma","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD > READ"},{"code":"SRCCR","name":"Signet Ring Cell Adenocarcinoma of the Colon and Rectum","score":45,"mainType":"Colorectal Cancer","tissue":"Bowel","hierarchy":"BOWEL > COADREAD > SRCCR"}]} ▶ list_studies { "search": "Colorectal Adenocarcinoma TCGA PanCancer" } ◀ result {"result":[{"cancer_study_identifier":"coadread_tcga_pan_can_atlas_2018","name":"Colorectal Adenocarcinoma (TCGA, PanCancer Atlas)","type_of_cancer_id":"coadread","sample_count":594,"has_guide":true,"url":"https://www.cbioportal.org/study/summary?id=coadread_tcga_pan_can_atlas_2018"}]} ▶ clickhouse_run_select_query { "query": "SELECT * FROM gene_mutation_variants_in_study(study = 'coadread_tcga_pan_can_atlas_2018', gene = 'KRAS') ORDER BY altered_samples DESC" } ◀ result {"rows":[{"mutation_variant":"G12D","mutation_type":"Missense_Mutation","altered_samples":58,"profiled_samples":534,"frequency_pct":10.9,"total_mutation_events":58},{"mutation_variant":"G12V","mutation_type":"Missense_Mutation","altered_samples":49,"profiled_samples":534,"frequency_pct":9.2,"total_mutation_events":49},{"mutation_variant":"G13D","mutation_type":"Missense_Mutation","altered_samples":37,"profiled_samples":534,"frequency_pct":6.9,"total_mutation_events":37},{"mutation_variant":"A146T","mutation_type":"Missense_Mutation","altered_samples":16,"profiled_samples":534,"frequency_pct":3,"total_mutation_events":16},{"mutation_variant":"G12C","mutation_type":"Missense_Mutation","altered_samples":15,"profiled_samples":534,"frequency_pct":2.8,"total_mutation_events":15},{"mutation_variant":"G12A","mutation_type":"Missense_Mutation","altered_samples":10,"profiled_samples":534,"frequency_pct":1.9,"total_mutation_events":10},{"mutation_variant":"G12S","mutation_type":"Missense_Mutation","altered_samples":8,"profiled_samples":534,"frequency_pct":1.5,"total_mutation_events":8},{"mutation_variant":"Q61H","mutation_type":"Missense_Mutation","altered_samples":4,"profiled_samples":534,"frequency_pct":0.7,"total_mutation_events":4},{"mutation_variant":"K117N","mutation_type":"Missense_Mutation","altered_samples":4,"profiled_samples":534,"frequency_pct":0.7,"total_mutation_events":4},{"mutation_variant":"Q61K","mutation_type":"Missense_Mutation","altered_samples":3,"profiled_samples":534,"frequency_pct":0.6,"total_mutation_events":3},{"mutation_variant":"G12R","mutation_type":"Missense_Mutation","altered_samples":2,"profiled_samples":534,"frequency_pct":0.4,"total_mutation_events":2},{"mutation_variant":"G13C","mutation_type":"Missense_Mutation","altered_samples":2,"profiled_samples":534,"frequency_pct":0.4,"total_mutation_events":2},{"mutation_variant":"Q61R","mutation_type":"Missense_Mutation","altered_samples":2,"profiled_samples":534,"frequency_pct":0.4,"total_mutation_events":2},{"mutation_variant":"A59T","mutation_type":"Missense_Mutation","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"R68S","mutation_type":"Missense_Mutation","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"L19F","mutation_type":"Missense_Mutation","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"Y71C","mutation_type":"Missense_Mutation","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"A11_G12dup","mutation_type":"In_Frame_Ins","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"P34L","mutation_type":"Missense_Mutation","altered_samples":1,"profiled_samples":534,"frequency_pct":0.2,"total_mutation_events":1},{"mutation_variant":"A146V","mutation_type":"Missense_Mutation","alter … (1004 more chars) ═ answer (success) Note that `A11_G12dup` is a duplication event spanning residues 11–12, which technically touches codon 12 — I've flagged it below but excluded it from the "non-codon-12" total since it overlaps that position. ## KRAS mutations at positions other than codon 12 **Study:** Colorectal Adenocarcinoma (TCGA, PanCancer Atlas) — `coadread_tcga_pan_can_atlas_2018`, 534 samples profiled for KRAS mutations (sample-level). | Variant | Type | Samples | % of profiled | |---|---|---|---| | G13D | Missense | 37 | 6.9% | | A146T | Missense | 16 | 3.0% | | K117N | Missense | 4 | 0.7% | | Q61H | Missense | 4 | 0.7% | | Q61K | Missense | 3 | 0.6% | | G13C | Missense | 2 | 0.4% | | Q61R | Missense | 2 | 0.4% | | A59T | Missense | 1 | 0.2% | | R68S | Missense | 1 | 0.2% | | L19F | Missense | 1 | 0.2% | | Y71C | Missense | 1 | 0.2% | | P34L | Missense | 1 | 0.2% | | A146V | Missense | 1 | 0.2% | | Q61P | Missense | 1 | 0.2% | | A155D | Missense | 1 | 0.2% | | Q22K | Missense | 1 | 0.2% | | Q61L | Missense | 1 | 0.2% | | Q61E | Missense | 1 | 0.2% | | E98* | Nonsense | 1 | 0.2% | | *A11_G12dup (spans codon 12, listed for completeness)* | In-frame Ins | 1 | 0.2% | **Totals:** 79 samples (14.8% of profiled) carry a non-codon-12 KRAS mutation, vs. the excluded G12* variants (G12D 58, G12V 49, G12C 15, G12A 10, G12S 8, G12R 2 = 142 samples, 26.6%) that were left out per your request. Codon 13 and codon 61 hotspots dominate the non-G12 set, consistent with KRAS's known mutational hotspot architecture in colorectal cancer. Here are direct links to explore this further on cBioPortal: [View KRAS mutations in Results View](https://www.cbioportal.org/results/mutations?cancer_study_list=coadread_tcga_pan_can_atlas_2018&gene_list=KRAS&tab_index=tab_visualize&Action=Submit) — Mutations tab shows the lollipop plot with all variants, including the non-G12 ones above.