ASCO 2010 & ANR 2010 ~ Survival after neuroblastoma relapse

Clinical and biological features predictive of survival after relapse of neuroblastoma: A study from the International Neuroblastoma Risk Group (INRG) Database.

Citation: J Clin Oncol 28:15s, 2010 (suppl; abstr 9518)

Wendy London is the Lead Statistician for neuroblastoma research for the Children’s Oncology Group (COG), and Data Center Statistics Committee Chair for the International Neuroblastoma Risk Group (INRG) project and has recently joined the team at Boston Children’s/Dana-Farber.

Dr London spoke on this topic at both ASCO 2010 (15 minute presentation on Monday for the Pediatric Oncology II session) and at ANR 2010 (25 minute presentation during the Monday Neuroblastoma Update Course)  and another 15 minute presentation on this same topic was given by by Victoria Castel on Thursday during the clinical plenary session. Three presentations–two at ANR!  This alone gives you an idea of the importance of this study–the largest ever done on this topic.

As I was preparing to report on this study, I saw that OncologySTAT.com (an excellent source of trustworthy oncology information by Elsevier, a world-leading publisher of medical information)  just released a report of their own. I highly encourage you to read their article.

Of 8800 INRG patients, 2266 experienced a “non-death first event.”

The INRG database includes all risk groups diagnosed from 1990 to 2002 in North America, Europe, Japan, and Australia.

Events are defined as relapse, progression, or second malignancy. Death as a first event was not included in this study.

Although prognostic factors are used to stratify treatment at diagnosis, no one has previously analyzed what factors are predictive of outcome post-relapse.  This study posed the question: is time-to-relapse a factor affecting outcome? Are there any other factors affecting outcome?

Of all the children who had events, median follow-up was 3.6 years (1 day to 13.7 years) and the characteristics of these children were:

• 73% ≥ 18 months old
• 72% were stage 4
• 33% were MYCN amplified

The median time to relapse for the 2266 children who had events was 13.2 months with a range of 1 day to 11.4 years. An anecdotal aside, I happen to know a fellow who relapsed 13.5 years after high-risk diagnosis, obviously not included in this data although he was diagnosed at Boston Children’s in 1991. He survived almost 5 years post-relapse.

The overall survival at 5 years after first event (all risk groups) is 20% ± 1%.

Those who had a first event in less than 1 year from diagnosis (n=1012) had approximately 25% overall survival and those who had first event after 1 year (n=1254) had about 10% overall survival.

When looking at those who relapsed before (n=2081) and after (n=184) 3 years, the gap closes at close to 20% survival.

The risk of death differs over time.

Time-to-first-event, age >18 mo, stage 4, MYCN amplified, diploidy, high MKI, undifferentiated grade, and 1p aberration were significantly predictive of death after relapse (p<0.0001), but not 11q aberration. Compared to children who had a first event more than 6 mo from diagnosis, those who relapsed 6-<18 mo from diagnosis had increased risk of death, while relapses ≥18 mo from diagnosis had decreased risk of death. Shorter time- to-first-event was not independently predictive of death after adjustment for undifferentiated grade, high MKI, MYCN amplification, or diploidy.

In a survival tree regression analysis that adjusted for time-to-relapse, disease stage was identified as the most highly significant variable for survival post relapse. Stage 4 patients (n=1578)  had a 5-year survival of 8% ± 1%, compared with 52% ± 3%  for those who were stage 1, 2, 3, or 4S (n=622).

Three groups were defined as salvageable for relapse treatment:

• stage 4, with nonamplified MYCN, and less than 18 months of age.
• stage 1, 2, 3, or 4S with MYCN amplification.
• stage 1, 2, 3, or 4S with nonamplified MYCN and undifferentiated grade histology.

Patients who had stage 4 disease and MYCN amplification had a 5-year survival of 4% ± 1% , compared with 12% ± 2% for stage 4 patients with nonamplified MYCN.

This information can help stratify children for relapse therapies.

NOTE: None of this data included how the children were treated for relapse. I am hoping this work will eventually lead to a rational plan for relapse therapy.

My take on this report? There WERE survivors in every group of relapse children….