Somatostatin may be safe option for certain tumors during pregnancy
In some patients, pregnancy can speed progression of neuroendocrine tumors
For about one-third of women with a neuroendocrine tumor — or an abnormal mass of tissue that forms from hormone-releasing cells, such as those in the pancreas — pregnancy may cause the tumor to grow faster, but somatostatin analogues may be a safe treatment option to slow down its growth, a small study has found.
To confirm these findings, “further robust studies are needed,” researchers wrote in the study “Neuroendocrine tumours and pregnancy: Real-world data from an European Neuroendocrine Tumour Centre of Excellence,” which was published in the Journal of Neuroendocrinology.
A neuroendocrine neoplasm or tumor develops from cells that may release higher-than-normal amounts of hormones into the blood in response to signals from the nervous system, causing symptoms. Such tumors are less common in younger populations, but their incidence “has increased over the years,” according to the researchers.
It can be difficult for doctors to control symptoms of a neuroendocrine tumor during pregnancy because there are limited data on how to best treat a pregnant woman while ensuring the health of both the mother and the baby. This is because “pregnant women are excluded from most clinical trials,” the researchers wrote.
Researchers studied 18 pregnant women with neuroendocrine tumors
Now, a study at the Royal Free Hospital in London, in the U.K., which is part of the European Neuroendocrine Tumor Society network of centers of excellence, looked at the experiences of 18 pregnant women (22 pregnancies) who developed a neuroendocrine tumor between 2015 and 2023.
On average, the women were 29.5 years old when they received their diagnosis of a neuroendocrine tumor. Thirteen women (15 pregnancies) already had a diagnosis before they got pregnant. The diagnosis was made during pregnancy in five cases and in the postpartum period in two.
Nearly half (44%) of the women had developed a pancreatic neuroendocrine neoplasm, and five (28%) had developed a tumor in the mid-gut. For the remaining five women (28%), the tumor had developed elsewhere in the body. By the time they were diagnosed, two-thirds (67%) of the women had metastatic disease, meaning that cancer cells had spread to other parts of the body.
Of the eight women who developed pancreatic tumors, four had intermediate-grade tumors, three had low-grade tumors, while the histological grading was not available for the remaining patient. Low grade means that tumor cells grow slowly and have a low rate of proliferation, while moderate-grade tumors show a higher rate of proliferation and have a higher potential for metastasizing.
To measure how fast each tumor grew, doctors calculated the tumor growth rate (TGR) based on computed tomography or MRI scans obtained before and after pregnancy. Some tumor samples were tested for estrogen and progesterone receptors to see if these hormones affected the TGR.
Of the 22 pregnancies, 19 (86%) resulted in a live birth, with four babies delivered preterm, or before 37 weeks of gestation. Three premature babies required neonatal intensive care. Three women (14%) had a miscarriage during their first trimester of gestation.
Pregnancy per se may accelerate tumour progression, and patients should be counselled regarding this possibility.
Tumor growth rate increased after pregnancy
On average, the TGR before pregnancy was negative, with tumor size decreasing by 0.8% over time. However, after pregnancy, the average TGR was positive, by 0.96%, indicating tumor growth. In two patients without enough data to calculate the TGR before pregnancy, new lesions appeared, suggesting disease progression.
Some tumors tested positive for estrogen and progesterone receptors. An increased production of these two hormones, which play a key role in reproduction, could explain faster tumor growth during pregnancy, the researchers noted.
Five women (six pregnancies) received treatment with a long-acting somatostatin analogue, either octreotide (marketed as Sandostatin, among others) or lanreotide (marketed as Somatuline, among others). A somatostatin analogue is a lab-made version of somatostatin, a naturally occurring hormone that can stop other hormones from being produced by the body.
All five women treated with a somatostatin analogue delivered healthy babies without any side effects or complications, and had stable disease, with no tumor growth postpartum.
“Pregnancy per se may accelerate tumour progression, and patients should be counselled regarding this possibility,” the researchers wrote. However, “somatostatin analogues appear to be safe during pregnancy.”
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