Metformin combined with insulin in women with gestational diabetes mellitus: a propensity score-matched study

AIM

Metformin use in gestational diabetes (GDM) is a common practice. Although its use in combination with insulin might be advantageous, it was never formally tested. We studied whether combined treatment was associated with better obstetric or neonatal outcomes compared to insulin alone.

METHODS

This is a retrospective study, using the Portuguese National Registry of GDM (2012-2017), of women treated with insulin ± metformin. Primary endpoints were obstetric and neonatal complications. Secondary endpoints were gestational weight gain (GWG) and insulin dose. A propensity score-matched analysis was performed to balance the distribution of age, BMI, insulin treatment duration, HbA1c, first trimester diagnosis of GDM and previous GDM or macrosomia. Women treated with metformin plus insulin and insulin only were then compared.

RESULTS

A total of 4034 women were treated with insulin or insulin plus metformin (10.2%). After propensity score matching, we studied two groups of 386 patients. Obstetric and neonatal complications were similar. Women treated with metformin plus insulin had 201 (52.1%) obstetric complications versus 184 (47.7%) in insulin-only group, p = 0.22; and 112 (29.0%) neonatal complications versus 96 (24.9%), p = 0.19. Patients treated with metformin plus insulin had similar GWG, excessive weight gain and insulin dose compared to the insulin-only group.

CONCLUSIONS

Women with GDM treated with insulin plus metformin had similar obstetric and neonatal complications, weight gained and insulin dose compared to those only treated with insulin.

Second Primary Cancer in Patients with Differentiated Thyroid Cancer: Does Radioiodine Play a Role?

BACKGROUND

Well-differentiated thyroid cancer (WDTC) is the most common endocrine neoplasia, and its incidence is rising. Studies have reported an increased risk of second primary cancer (SPC) in WDTC survivors, but its relationship with radioiodine treatment (RAIT) and other risk factors remains controversial. This study evaluated whether RAIT is an independent risk factor for SPC in WDTC patients.

METHODS

This was a retrospective single-center study. A total of 2031 patients with WDTC diagnosed between 1998 and 2009, treated and followed at the authors' tertiary cancer center, were included.

RESULTS

The median age of patients was 48 years (range 5-90 years); 83% were women and 77% underwent RAIT. The median follow-up was 8.8 years (range 5.0-17.0 years). A total of 130 SPC were diagnosed: 108/1570 (6.9%) received RAIT (RAIT+) and 22/461 (4.8%) did not (RAIT-). The most common SPC was breast cancer (31%), followed by genitourinary and gastrointestinal cancer (18% each). The 10-year cumulative incidence of SPC was 8.2% in RAIT+ and 4.5% in RAIT-. The absolute risk increase in the RAIT+ group versus the RAIT- group at 10 years of follow-up was 0.039 [confidence interval (CI) 0.011-0.067] per patient-year. The number needed to harm (NNH) was 25.6 [CI 15.0-87.2], indicating that on average during a 10-year follow-up period, there is one additional case of SPC for every 26 patients receiving RAIT. When controlling for age, sex, and familial and personal histories of cancer, there was an 84% increase in the risk of SPC in the RAIT+ group compared to the RAIT- group (p = 0.026; relative risk = 1.84 [CI 1.02-3.31]). There was an association between SPC incidence and total cumulative activity administered, which was statistically significant >200 mCi. The incidence of SPC was higher in both the WDCT and the RAIT+ cohorts compared to the general population (standardized incidence ratios = 1.32 and 1.40, respectively).

CONCLUSION

These results indicate that in spite of the low incidence of SPC in WDTC patients, the risk is increased after RAIT, particularly for activities >200 mCi. Thus, considering the excellent survival of patients with WDTC, clinicians need to weigh the risks and benefits of RAIT, especially in patients with low-risk thyroid cancer.

Review of clinical and pathological features of 93 cases of well-differentiated thyroid carcinoma in pediatric age at the Lisbon Centre of the Portuguese Institute of Oncology between 1964 and 2006

INTRODUCTION

Thyroid carcinoma is the most common endocrine malignancy. In childhood, thyroid carcinoma usually behaves aggressively and relapses frequently. Nevertheless, it has a favorable prognosis. Our aim is to present our experience with pediatric well-differentiated thyroid carcinoma (WDTC) treated at the Portuguese Institute of Oncology in Lisbon (L-PIO), between 1964 and 2006.

METHODS

Review of clinical files of WDTC in≤18-year-old patients selected from the databases of the Endocrinology Service of L-PIO and the South Portugal Regional Cancer Registry (SPCR).

RESULTS

93 cases of WDTC were found. Of these, 70 (75.3%) were girls. The median age was 15 years old (range 5-18) with a median follow-up time of 15.1 years (range 0.2-47.8). The most common histological diagnosis was papillary carcinoma of the classical variant (n=60, 64.5%). Initial staging showed locoregional dissemination in 27 (29.0%) patients and distant metastasis in 16 (17.2%) patients. Median age was lower in patients with distant disease than in patients with locoregional disease or with disease confined to the thyroid (P=0.007). After the initial treatment, 44 (47.3%) patients were in remission and 46 (49.5%) had persistent disease (lost follow-up in 3). Of the disease-free patients after initial treatment, 11 (25.0%) relapsed later. At the last observation, most patients (n=63, 67.7%) showed no evidence of disease.

CONCLUSION

Our study demonstrates that children with distant metastatic disease are younger than children with a less aggressive disease. However, in both groups the response to treatment is favorable and the prognosis is usually excellent.