A recent study reveals that delays in the treatment of posterior uveal melanoma increased the risk of metastatic death, adding to evidence addressing the question of how primary tumor treatment affects prognoses for patients.
While many tumor characteristics have been linked to risk of metastasis, the impact of treatment is still up for debate, the investigators note in their Ophthalmology article "Delays between Uveal Melanoma Diagnosis and Treatment Increase the Risk of Metastatic Death". “On the one hand, successful interventions stop tumors from growing larger and seeding additional metastases…On the other hand, some experts argue that metastatic seeding occurs early in the disease, likely even before the primary tumor is diagnosed,” they write. This argument suggests primary tumor treatment may not be as effective in mitigating negative outcomes if metastatic seeding occurs before diagnosis and, indeed, before treatment can be initiated.
For example, “evidence from major studies, such as the Collaborative Ocular Melanoma Study, suggests that immediate treatment might not significantly influence overall survival rates for medium-sized tumors,” the researchers note in a discussion on the current literature. “There was no significant difference in overall survival between patients who received immediate treatment for medium-sized tumors and those who initially deferred treatment and opted for the Natural History Study.” In the cited study, 22 patients decided, after a mean of 1.4 years, to undergo treatment.
In another recent analysis, the investigators themselves found that 88% of patients diagnosed with small to medium-sized tumors who delayed treatment for more than 5 years after diagnosis developed metastases by long-term follow-up.
The current study, conducted at St. Erik Eye Hospital in Sweden, followed 1,145 patients diagnosed with uveal melanoma (UM) from 2012 to 2022 to examine “the correlation between the interval from diagnosis to treatment and the risk of metastatic death.”
Overall, the investigators found that “increasing time between diagnosis and treatment of posterior UM is associated with increased risk for metastatic death.” Further, patients treated more than one month after diagnosis showed a significantly higher risk of metastatic death, particularly in AJCC (American Joint Committee on Cancer) stages II and III. The study also found that the risk of metastatic death increased by 1% for every additional 10-day delay in treatment.
While the researchers provide a reminder of the spectrum of tumor behavior—especially that not all early metastatic seeding is indicative of aggressive traits from the onset—they conclude that early diagnosis and treatment is better: “There can be little room for doubt: A portion of tumors that do not initially have aggressive traits will develop those if they are left untreated or if they recur after primary treatment. These tumors will then be at increased risk for metastasis. If tumors are treated before such aggressive traits are developed, even if only in a small portion of tumors, survival should be improved.”
A full list of author disclosures can be found in the published research.
