Dartmouth team confirms elevated kidney cancer signal in Merrimack, outlines pilot study and outreach plan

A Dartmouth research team told the HB 737 commission on March 14 that an updated cancer‑registry analysis confirms an elevated rate of kidney cancer in Merrimack, New Hampshire for the 2013–2018 period and described plans for a pilot study to test methods for a larger, definitive investigation.

Associate Professor Megan Romano, of Dartmouth College and Dartmouth Geisel School of Medicine, and Dr. Lucas (Doctor) Salas, an assistant professor of epidemiology, said the team’s revised analysis of New Hampshire State Cancer Registry data — which incorporated delayed Veterans Affairs case reports — shows a statistically significant excess of renal cell carcinoma in Merrimack for 2013–2018. The team reported an SIR of 1.65 for Merrimack in that interval, with 45 reported cases in the period examined; Dr. Salas told the commission that confidence intervals for that period excluded 1.0, indicating statistical significance.

The presenters emphasized that SIRs indicate a signal of excess cases but do not identify cause. Dr. Salas reviewed standard interpretation: an SIR greater than 1 suggests more cases were observed than expected based on the comparison population, and 95% confidence intervals are required to assess whether an observed excess is unlikely to be due to chance. He said the team separated kidney tumors from renal‑pelvis tumors because the two have different molecular origins and risk profiles; the analysis found no excess in renal‑pelvis cancers.

Romano described Phase 3 as a feasibility step that combines community engagement, cancer‑registry analysis, a population survey and a pilot enrollment effort. The team completed four community engagement studios (38 participants, ages 21–76, 71% women, about 65% from Merrimack) and a November 2024 feasibility survey conducted by the University of New Hampshire Survey Center (1,183 Granite State Panel respondents; oversample of the nine‑town area). Themes from community input included concern about PFAS and other contaminants, interest in research that leads to action, the need for broad outreach and multiple communication channels, concerns about data access and trust, and suggestions that modest financial incentives could help recruitment.

The pilot study will seek to enroll about 70–100 adult New Hampshire residents who have lived, worked or lived and worked in the nine‑town area for at least 12 months. Participants will include people with and without diagnosed renal cell carcinoma. All participants will complete detailed questionnaires; a subset of about 20 participants will be asked to provide water, urine and blood samples. Romano said the pilot is not designed to determine causation; rather, it is intended to demonstrate feasibility and generate preliminary data to support funding applications for a larger study.

The team said it has started the institutional review board submission and expects the pilot to proceed pending IRB approval. Romano estimated that a larger definitive study would likely require a 5‑year timeline and approximate direct research costs on the order of $500,000 per year (an R01‑scale NIH grant), and the team is exploring multiple funders — NIH, Department of Defense, American Cancer Society and private foundations — while noting competitive success rates and current uncertainty in the federal funding environment. The presenters said many Dartmouth faculty are donating time to keep the project moving and that the pilot will help the team refine recruitment and biospecimen collection methods before seeking larger grants.

Commission members asked about small‑number stability, time‑period choices, and residential histories. Dr. Salas said grouping years and excluding renal‑pelvis cases were steps to improve comparability across registry classification changes; he also emphasized limits of short recent intervals (for example, three‑year slices) and urged caution in interpreting small counts. Romano said the pilot will collect residential histories and data about water source and household filtration or bottled‑water use to better account for past exposures.

The presenters encouraged continued community outreach and said the project will keep an online feedback form open through the end of the team’s contract with the state. They invited commission members to suggest community events for recruitment. Romano and Salas answered questions from commission members and the assembled public advisory participants before the commission moved on to other business.

Ending: The Dartmouth team said Phase 3 work will continue through June with a focus on the pilot protocol and IRB approval; the presenters said they will share their written materials with the commission and will return with updates on pilot enrollment and any changes to analytic plans.