Tens of thousands of patients were waiting for routine treatment at Hampshire Hospitals Trust in January, new figures show.
It comes as a health and social care think tank warned of a "continued backlog for care" in England.
NHS England figures show 51,951 patients were waiting for non-urgent elective operations or treatment at Hampshire Hospitals NHS Foundation Trust at the end of January – up slightly from 51,918 in December, but a decrease on 52,966 in January 2024.
Of those, 1,559 (3%) had been waiting for longer than a year.
The median waiting time from referral to treatment at Hampshire Hospitals Trust was 15 weeks at the end of January – the same as in December.
Nationally, 6.3 million people were waiting to start treatment at the end of January — up slightly from 6.2 million at the end of December.
But an estimated 7.4 million treatments were waiting to be carried out at the end of January, which was down from 7.5 million at the end of last year.
Thea Stein, chief executive of the Nuffield Trust, welcomed the drop but warned improvements must still be made.
She said that, although the figures highlight progress has been made on the number of treatments waiting to be carried out nationally, efforts are "dwarfed by the magnitude of the continued backlog for care".
As NHS leaders meet today to discuss funding, she said "it is crystal clear" the financial pressures faced by the NHS are linked to a higher demand for healthcare, a "poor or patchy" provision of social care, and a lack of funding in primary and community care.
Separate figures show 1.6 million patients in England were waiting for a key diagnostic test in January – the same as in December.
At Hampshire Hospitals Trust, 16,395 patients were waiting for one of 13 standard tests, such as an MRI scan, non-obstetric ultrasound or gastroscopy at this time.
Of them, 7,116 (43%) had been waiting for at least six weeks.
Other figures show cancer patients at Hampshire Hospitals Trust are not being seen quickly enough.
The NHS states 85% of cancer patients with an urgent referral should start treatment within 62 days.
But NHS England data shows just 77% of cancer patients urgently referred to Hampshire Hospitals Trust in January began treatment within two months of their referral.
That was down from 82% in December, but up from 70% in January 2024.
Professor Pat Price, leading oncologist and chair of Radiotherapy UK, said: "Today's cancer data shows that yet again we are going backwards, and the cancer crisis is only deepening.
"Cancer patients are still waiting too long, and stagnation at frighteningly bad waiting times cannot fall off the agenda."
She warned that, despite pressures on public funding, "the primary obligation must always be to deliver high-quality care".
"Cancer patients cannot afford further delays – cancer cannot be the collateral-timely treatment is the minimum they deserve," she added.
Health and Social Care Secretary Wes Streeting welcomed the drop in the NHS waiting list, but warned "there is still a long way to go" to fully address waiting times.
He added: "By delivering the 2 million more appointments we promised before the election, ending the strikes, and reforming the NHS to drive up productivity, we are putting the NHS on the road to recovery.
"Through the Prime Minister’s Plan for Change, we will cut the longest waiting times from 18 months to 18 weeks, so the NHS is there for you when you need it, once again."