(NEXSTAR) — Just months after sharing that he was cancer-free, “Full House” actor Dave Coulier says he has been diagnosed with a different form of cancer.

Coulier, 66, told the TODAY show on Tuesday that he was diagnosed with HPV-related oropharyngeal tongue cancer in October.

It’s unrelated to his previous diagnosis of non-Hodgkin lymphoma he received last fall. Earlier this year, Coulier shared that he was cancer-free while also confirming he had become a grandfather for the first time.

“To go through chemotherapy and feel that relief of whoah, it’s gone, and then to get a test that says, well now you’ve got another kind of cancer … it is a shock to the system,” Coulier told TODAY host Craig Melvin on Tuesday. He explained that he had no signs or symptoms of the new cancer, which was caught on a follow-up PET scan.

Doctors noticed “something at the base” of Coulier’s tongue, but an initial biopsy did not reveal anything. Another PET scan in October showed the growth on this tongue had grown.

This time, a biopsy was found to have cancerous cells. Coulier said he was diagnosed with P16-positive oropharyngeal squamous cell carcinoma, a type of tongue cancer.

There are several strains of HPV, 13 of which can cause multiple forms of cancer, according to UC Davis Health. Long-lasting infection from HPV 16 that goes untreated can allow the cell changes that become cancer, the National Cancer Institute explains.

About 1 in 59 men and 1 in 139 women will develop oral cavity or oropharyngeal cancer in their lifetime, the American Cancer Society reports. Cases have been slowly on the rise since the mid-2000s, an increase that the ACS attributes to more cancers being linked with HPV infection.

Treatment and outcomes for oropharyngeal cancers can vary; patients with a P16-positive diagnosis tend to fare better with treatment than those with a P16-negative diagnosis.

“It’s got a 90% curability rate,” Coulier said Tuesday. “The doctor said the prognosis is good, but we’re going to start radiation immediately.”

Coulier, beloved for his role as Uncle Joey on “Full House,” told TODAY that he expects to finish radiation by the end of the year. Then, doctors believe his cancer will be cured.

“The silver lining here is that I had cancer, which helped me detect my other cancer. It seems crazy to be making that statement, but it’s true,” he added.