Patients Accept Watchful Waiting for Low-Risk Thyroid Cancer

Pam Harrison

October 29, 2019

More than half of patients with low-risk papillary thyroid microcarcinomas (PTMCs) in Japan are assigned to active surveillance — as recommended by Japanese guidelines — rather than immediate surgery, according to the first survey of its kind there on the current management of low-risk PTMCs.

"This survey shows a high rate of active surveillance for PTMCs in Japan," Iwao Sugitani, MD, PhD, Graduate School of Medicine, Nippon Medical School, Tokyo, Japan, and colleagues write in their article published in Thyroid.

"However, marked differences in the indication and recommendation for active surveillance among institutions were also observed," they stress.

"To increase the use of active surveillance for PTMC, physicians, primary care doctors, patients, and their families should be educated," and the socio-medical environment should also be improved, they recommend.

"Most of the Time, These...Cancers Don't Grow and They Don't Spread"

In the United States, adoption of active surveillance for small intrathyroidal thyroid cancers remains in its early stages. A very limited number of centers offer this so-called watchful waiting as an alternative to immediate surgery, as observed in an article published earlier this year (JAMA. 2019;321:2020-2021).

And this is despite the American Thyroid Association recommending active surveillance for the same tumor type in 2015.

The Memorial Sloan Kettering Cancer Center (MSKCC) in New York City is one of the US centers that does offer watchful waiting.

"We now have over 500 patients with small, low-risk papillary thyroid cancer on active surveillance, and we use similar characteristics as the Japanese use to define low risk," Luc Morris, MD, attending head and neck surgeon, MSKCC, told Medscape Medical News.

"It's important to say that surgery, particularly thyroid lobectomy for a small thyroid cancer, is a very safe operation and a very reasonable approach, so I don't think surgery is wrong," he emphasized.

"But I think the thing that we want to aspire to as surgeons is, 'Can we engage in shared decision-making with our patients and help them decide what makes more sense to them?'"

Then, if their tumor does grow or change and patients eventually need surgery, "we can do the exact same operation then that we would have done [initially] so we don't lose anything by waiting."

"But what we gain is a very high chance that the patient will never need surgery because, most of the time, these small cancers don't grow and they don't spread," Morris stressed. 

Japanese Guidance Followed Prospective Trials

The recommendation for watchful waiting was included in joint guidelines by the Japan Association of Endocrine Surgery (JAES) and Japanese Society of Thyroid Surgery (JSTS) in 2011.

This followed two Japanese prospective trials of active surveillance in low-risk PTMC of tumors 1 cm or less, which included serial ultrasonography in lieu of immediate surgery. Extended follow-up demonstrated that most tumors remained unchanged or decreased in size compared with baseline.

And when patients with tumors that exhibited growth or lymph node metastases did undergo surgery, complete tumor and metastatic lymph node excision were routinely achieved and none of the patients died from thyroid cancer.

In 2017, the total number of thyroid surgeries in Japan was 12,710, among which low-risk PTMCs accounted for some 18% of all surgeries, say Sugitani and colleagues, by way of background in their article.

To identify how asymptomatic PTMCs are currently managed in Japan, they sent a questionnaire in August 2018 to member institutions of JAES and JSTS asking how they manage PTMCs.

Only 11.4% of the institutes responded, the investigators note.

However, almost 71% of the responses came from institutions certified by JAES or JSTS, and thus responses reflect how most PTMC patients in Japan are managed.

For suspicious tumors on ultrasound, 13.4% of respondents conducted routine cytological examination using fine needle aspiration cytology (FNAC), and slightly over half (51.5%) conducted routine cytological examination only if tumors were larger than 0.5 cm.

In Japan, FNAC for nodules in excess of 0.5 cm with highly suspicious ultrasound features has been recommended by the Japan Association for Breast and Thyroid Sonology since 2016.

Some 28% of respondents carried out a routine cytological examination only if tumors were larger than 1 cm.

"Most of the responding institutions present the patients with two options, active surveillance and surgery," the authors explain.

Slightly over 31% of physicians recommended active surveillance as first-line management, they report.

On the other hand, 26% of institutions still recommend immediate surgery, despite studies that support the safety of active surveillance and its superiority over immediate surgery with respect to adverse outcomes.

Conditions that prompted institutions to recommend surgery over active surveillance included tumors located near the dorsal capsule of the thyroid lobe, multiple lesions, and tumor size close to 1 cm.

At MSKCC, 70-75% of Patients Accept Active Surveillance

As probably the earliest adopter of active surveillance in the United States, the MSKCC program was modeled after the Japanese experience and launched because its instigator, R. Michael Tuttle, MD, an endocrinologist at MSKCC, was convinced that the Japanese data were robust enough to offer the same approach to their own patients.

Morris explained that the key feature for active surveillance is tumor size.

"We will go up to 2 cm as long as the tumor is not showing a lot of contact with the posterior capsule but the vast majority of patients in our active surveillance program have tumors between 1 and 1.5 cm," he explained.

Candidates for active surveillance also have to be free from any suspicious or involved lymph nodes or any evidence of extrathyroidal extension, Morris noted.

And delivering this care takes a multidisciplinary team, he stressed.

However, the MSKCC team feels strongly that the surgeon is the most appropriate person to counsel potential candidates for the active surveillance program.

"Many surgeons in North American believe their patients will not accept active surveillance," Morris said. 

But it all depends on the approach. If the surgeon reassures the patient that their cancer is not an emergency — that it is not going to threaten their life or health — most patients are ready to participate in the program, he explained.

When the program was initiated, team members expected about 25% of patients chose active surveillance over surgery as initial treatment, especially in New York City, where patients are very proactive. "They want their surgery tomorrow," Morris noted.

To their surprise, the overall acceptance rate of active surveillance at MSKCC is 70% to 75%, he said.

"When I offer active surveillance, about 95% of patients will accept it," Morris concluded.

Thyroid. Published online September 25, 2019. Full text

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