Some 17 months after becoming monarch, King Charles III has been diagnosed with cancer. Here's what we know as of Tuesday:

- Detected 'early' -

Buckingham Palace has not specified the type of cancer the 75-year-old king is suffering from, but indicated that it was not prostate cancer.

The cancer was detected "early", according to Prime Minister Rishi Sunak, which theoretically improves the chances of recovery.

The most common cancers in the UK -- where about 1,000 new cases are detected each day -- are breast, lung, prostate and colon cancer, which together account for 53 percent of new cases, according to Cancer UK.

People over the age of 75 represent 36 percent of new cancer cases diagnosed each year.

- Diagnosis after surgery -

The king returned to London on Monday from his Sandringham residence in eastern England, where he received initial treatment.

He learned he had cancer after surgery for an enlarged prostate at the end of January.

He underwent a corrective procedure for his benign prostate condition during a three-night stay at the private London Clinic.

Tests carried out during his stay detected the cancer.

- Diagnosed last week -

The king was informed of his diagnosis at the beginning of last week, according to the Daily Mail newspaper, but was still seen attending church at Sandringham with Queen Camilla on Sunday and waving to wellwishers.

The king took the time to inform his close family members -- notably his son Harry, with whom relations have been tense for months -- before making his illness public "to avoid speculation".

- No details on treatment -

Charles "remains wholly positive" and is looking forward "to returning to full public duty as soon as possible", according to the palace.

The palace has not given details of his treatment but many cancer patients are treated with chemotherapy, a drug combination usually administered by intravenous infusion.

- PM meetings to continue -

Despite being in his eighth decade, the king enjoys an active lifestyle including skiing and has only had minor health issues in the past.

On the advice of his doctors, however, he has postponed public engagements to undergo treatment although he will continue to "undertake state business and official paperwork as usual".

Sunak, whom he meets every week, said on Tuesday he would "continue to communicate" with the king "as usual".