The Neurosurgery Signal — Signal, Not Noise

Rapid review note

Journal Club is a rapid, AI-assisted appraisal layer. It highlights study design, effect estimates, and practice relevance, but it is still a briefing, not a replacement for the paper.

For education only. Not medical advice.

Paper snapshot

Rapid study overview

Open paper

DOI

10.1200/JCO.2011.35.8598

PMID

22851558

PICO

Population

Adults (age ≥18) with supratentorial WHO grade 2 low-grade glioma (astrocytoma, oligodendroglioma, or mixed oligo-astrocytoma) who were unfavorable risk: age ≥40 years with any resection extent, or age 18-39 years with subtotal resection/biopsy.

Intervention

Radiation therapy (RT) followed by six cycles of PCV chemotherapy (procarbazine, lomustine, vincristine).

Comparator

Radiation therapy (RT) alone.

Outcomes

Overall survival (OS), progression-free survival (PFS), and post hoc analysis of OS in 2-year survivors.

Design

Type

Phase III randomized controlled trial

Randomized

Yes

Multicenter

Yes

Blinded

Not reported

Follow-up

Median not reported; accrual 1998-2002, analysis at time of publication.

Primary endpoint

Overall survival (OS) - not statistically significant in primary analysis.

Secondary endpoints

Progression-free survival (PFS)
Post hoc analysis of OS in 2-year survivors

Practice impact

What this means

RTOG 9802 randomized 251 adults with unfavorable-risk low-grade glioma to RT alone vs RT+PCV. Primary analysis showed improved PFS (HR 0.6) but no significant OS benefit. Post hoc analysis found that among 2-year survivors, RT+PCV improved 5-year OS probability (74% vs 59%, HR 0.52). This suggests a delayed chemotherapy benefit, but results are exploratory.

Bottom line

RT+PCV improves PFS but not OS in primary analysis; post hoc analysis suggests delayed OS benefit for 2-year survivors.

Strength of evidence

moderate

Recommendation

consider change

Why it matters

Randomized trial with 251 patients
PFS benefit with HR 0.6 and log-rank P=0.005
Post hoc OS benefit in 2-year survivors (HR 0.52, P=0.02) but exploratory

What would change my mind

Long-term follow-up confirming OS benefit
Validation in temozolomide-based trials
Molecular subgroup analysis (IDH, 1p/19q) showing differential effects

Critical appraisal

How strong is the paper?

Methods critique

Risk of bias

Randomization performed; central pathology review; no blinding reported; post hoc analysis introduces bias.

Confounding

Stratified by age and resection extent; no major baseline imbalances reported.

Missing data

Not explicitly addressed; 251 patients accrued, 211 included in 2-year survivor analysis.

Multiplicity

Multiple comparisons (OS, PFS, post hoc subgroup) without adjustment; post hoc analysis not prespecified.

Notes

Post hoc analysis of 2-year survivors is exploratory
No details on treatment compliance or toxicity in this excerpt

Stats check

NNT

Not reported

Effect sizes

HR 0.72 (95% CI 0.47-1.10) for OS
HR 0.6 (95% CI 0.41-0.86) for PFS
HR 0.52 (95% CI 0.30-0.90) for OS in 2-year survivors

Absolute effects

5-year OS: 63% (RT) vs 72% (RT+PCV)
5-year PFS: 46% (RT) vs 63% (RT+PCV)
Median OS: 7.5 years (RT) vs not reached (RT+PCV)
Median PFS: 4.4 years (RT) vs not reached (RT+PCV)

Concerns

Primary OS endpoint not statistically significant (P=0.33)
Post hoc analysis not prespecified
PFS benefit with HR 0.6 but P=0.06 for modified Wilcoxon test

External validity

Who it applies to

Adults with supratentorial WHO grade 2 low-grade glioma who are unfavorable risk (age ≥40 or younger with subtotal resection/biopsy).

Who it does not

Patients with favorable risk (age 18-39 with gross total resection), pediatric patients, infratentorial tumors, or pilocytic astrocytomas.

Generalizability notes

Uses PCV chemotherapy, not temozolomide
Eligibility required central pathology review
Accrual 1998-2002; molecular markers (IDH, 1p/19q) not incorporated

Evidence trace

Source trace and metadata

Citations (3)

claim_id

methods_critique.risk_of_bias

locator

p. 1 Patients and Methods

quote

Patients were randomly assigned to RT alone or RT followed by six cycles of PCV.

claim_id

stats_check.effect_sizes

locator

p. 1 Results

quote

Median overall survival (OS) time and 5-year OS rates for RT versus RT + PCV were 7.5 years versus not reached and 63% versus 72%, respectively (hazard ratio [HR]; 0.72; 95% CI, 0.47 to 1.10; P = .33; log-rank P = .13).

claim_id

practice_impact.bottom_line

locator

p. 1 Conclusion

quote

PFS but not OS was improved for adult patients with LGG receiving RT + PCV versus RT alone. On post hoc analysis, for 2-year survivors, the addition of PCV to RT conferred a survival advantage, suggesting a delayed benefit for chemotherapy.

Metadata

Generated at

2026-03-06T13:41:29.251Z

Version

top 100 cited in past 20 years