Colorectal-Specific Radiation Dose and Chemotherapy Risk for Subsequent Colorectal Malignancies in Childhood Cancer Survivors: A Childhood Cancer Survivor Study (CCSS) Report
Bibliographic record
Abstract
PURPOSE Among childhood cancer survivors, we evaluated not previously explored relationships between colorectal subsequent malignant neoplasm (SMN) incidence and colorectum-specific radiation dose metrics currently used in radiation therapy (RT) planning and expanded upon previously reported chemotherapy associations. METHODS The Childhood Cancer Survivor Study (CCSS) includes 5-year survivors of childhood cancer diagnosed between 1970 and 1999. RT was assessed as mean colorectal dose (MCD) and the percent volume (V X Gy ) receiving ≥5, 10, 20, 30, and 40 Gy. Chemotherapy was assessed as cumulative doses for procarbazine and platinum agents, cyclophosphamide-equivalent doses for alkylating agents, and doxorubicin-equivalent doses for anthracyclines. Piecewise-exponential models and excess rate ratio (ERR) models evaluated dose-response relationships for the incidence of colorectal SMNs. Reference groups were those not receiving the assessed treatment(s). RESULTS Among 25,723 survivors (median follow-up = 28.5 years; range = 5.0-48.9), 104 colorectal SMNs were identified. A dose-response relationship was observed between MCD and colorectal SMN rates; incidence rate ratios (IRRs) for 10 to <20 Gy and ≥20 Gy were 3.6 (95% CI, 1.9 to 6.9) and 8.3 (95% CI, 3.9 to 17.8), respectively. When ≥20% of the colorectum volume was irradiated, IRRs increased with increasing volume. The V 20 Gy IRRs were 3.8 (95% CI, 1.9 to 7.6), 4.9 (95% CI, 2.0 to 12.0), and 8.7 (95% CI, 3.5 to 21.6) for irradiated volumes of 20% to <40%, 40% to <80%, and ≥80%, respectively. The IRR was 1.8 (95% CI, 1.0 to 3.0) for doxorubicin-equivalent dose ≥250 mg/m 2 , 3.7 (95% CI, 2.2 to 6.4) for cyclophosphamide-equivalent dose ≥6,000 mg/m 2 , and 4.5 (95% CI, 2.0 to 10.1) for platinum dose ≥450 mg/m 2 . For procarbazine dose, the IRR was 6.3 (95% CI, 3.0 to 13.2) for 4,200 to <7,036 mg/m 2 and 9.0 (95% CI, 4.3 to 18.9) for ≥7,036 mg/m 2 . In the absence of RT, colorectal SMN rates increased with exposure to any platinum-based agent (IRR, 3.8 [95% CI, 1.1 to 12.7]), alkylator (IRR, 4.8 [95% CI, 1.6 to 14.4]), or procarbazine (IRR, 16.9 [95% CI, 5.9 to 48.8]). Colorectal SMN rates increased linearly with procarbazine dose (ERR per 1,000 mg/m 2 = 73.0 [95% CI, 26.4% to 119.6%]) and MCD (ERR per 1 Gy = 20.8 [95% CI, 9.0% to 32.5%]). Quadratic ERR models did not improve data fit compared with linear ERR models. CONCLUSION These RT and chemotherapy dose-response relationships can better inform contemporary RT planning for pediatric patients and surveillance guidelines for high-risk survivors.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".