Thousands of Long Island cancer patients could lose access to their lifesaving treatments at Memorial Sloan Kettering Cancer Center (MSK).

MSK is set to lose in-network coverage with UnitedHealthcare at midnight as the two sides fail to reach a new contractual agreement as the July 1 deadline approaches.

Lee Kassler, of Plainview, receives treatments for a rare form of gastric cancer at MSK.

"I'm comforted in knowing they know what's going on with me,” he said. 

As the deadline approaches with no deal in sight, the Plainview grandfather worries what he and thousands of other patients will do next.

"Think about the 19 to 20,000 patients,” he said. "Come up with a solution."

United Healthcare declined an interview request from News 12, but said its top priority is to reach an agreement with MSK.

UnitedHealthcare CEO, New York Junior Harewood sent a statement to News 12 about the ongoing negotiations.

“Our top priority is to reach an agreement with MSK that is affordable for consumers and employers. We have proposed substantial rate increases that would continue to reimburse MSK at levels significantly higher than other National Cancer Institute-designated health systems in the New York City metro area. Unfortunately, MSK is demanding an approximate 30% price hike on average for its hospitals and physicians, including a 36% rate increase at MSKCC. MSK’s proposal would increase health care costs by more than $400 million and directly impact self-insured employers. We will remain at the negotiating table as long as it takes to renew our relationship with MSK. We ask MSK to join us there and provide a proposal people and employers can afford.”

A UHC spokesperson said an MSK proposal would result in higher costs for services like CT scans, MRIs, and mammograms.

MSK Cancer Center Chief Medical Officer Dr. Cardinale Smith says that’s not the case.

"UHC is really prioritizing profits over patients,” she said.

Dr. Smith says MSK’s latest proposal only asks for fair compensation from one of the nation’s largest health care insurance companies.

"We have better outcomes for our patients,” she said. “They're living longer, and we do that by driving down the total cost of care by about 4 to 16%."

Kassler says the last thing a cancer patient should worry about is where they will get their care from.

"Until UHC and MSK do reach a formal agreement, I'm still very uneasy,” he said.

Check with United Healthcare to see what care options are available with each individual plan.

MSK will hold a news conference Tuesday in Manhattan with cancer patients to address what they can do to continue their care.