Dynamics of PTH levels in the development of post-operative hypoparathyroidism

BACKGROUND

Post-operative hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of preoperative predictors could be helpful to identify patients at risk. This study aimed to evaluate the potential influence of preoperative PTH levels and their perioperative dynamics as a predictor of transient, protracted, and permanent post-operative hypoparathyroidism.

METHODS

A prospective, observational study that includes 100 patients who underwent total thyroidectomy between September 2018 and September 2020.

RESULTS

Transient hypoparathyroidism was present in 42% (42/100) of patients, 11% (11/100) developed protracted hypoparathyroidism, and 5% (5/100) permanent hypoparathyroidism. Patients who presented protracted hypoparathyroidism had higher preoperative PTH levels. The protracted and permanent hypoparathyroidism rate was higher in groups with greater preoperative PTH [0% group 1 (<40 pg/mL) vs. 5.7% group 2 (40-70 pg/mL) vs. 21.6% group 3 (>70 pg/mL); p = 0.03] and (0 vs. 8.3 vs. 20%; p = 0.442), respectively. The rate of protracted and permanent hypoparathyroidism was higher in patients with PTH at 24 h lower than 6.6 pg/mL and whose percentage of PTH decline was higher than 90%. The rate of transient hypoparathyroidism was higher in patients who showed a PTH decline rate of more than 60%. The percentage of PTH increase one week after surgery in patients with permanent hypoparathyroidism was significantly lower.

CONCLUSION

The prevalence of protracted hypoparathyroidism was higher in groups with higher preoperative PTH levels. PTH levels 24 h after surgery lower than 6.6 pg/mL and a decline of more than 90% predict protracted and permanent hypoparathyroidism. The percentage of PTH increase a week after surgery could predict permanent hypoparathyroidism.

Does Vitamin D Deficiency Really Increase the Risk of Post-surgical Hypoparathyroidism?

Purpose

Postoperative hypoparathyroidism is the most frequent complication after total thyroidectomy. The identification of preoperative predictors could be helpful to identify patients at risk. The aim of this study is to determine if preoperative vitamin D levels are related to transient, protracted, and permanent hypoparathyroidism.

Method

A prospective, observational study that includes 100 patients who underwent total thyroidectomy.

Results

Transient hypoparathyroidism was present in 42% of patients, 11% developed protracted hypoparathyroidism and 5% permanent hypoparathyroidism. The median preoperative Vitamin D levels were higher in patients who developed transient hypoparathyroidism than in patients without this complication (24 ng/mL [RIQ 13-31] vs. 17 ng/mL [RIQ 10-24]; p = 0.024). Patients with preoperative vitamin D levels below 20 ng/mL had a lower percentage of transient hypoparathyroidism (31.4% vs. 53.1%; p = 0.028). The prevalence of protracted and permanent hypoparathyroidism in both groups was similar. Patients with preoperative vitamin D levels lower than 20 pg/mL had higher median PTH levels 24 h after surgery, (37.7 ± 28.2 pg/ml vs. 23.6 ± 18.6 pg/ml; p = 0.037), and suffered a lower postoperative PTH decline (46.2 ± 35.4% vs. 61 ± 29%; p = 0.026).

Conclusions

Patients with vitamin D deficiency had a lower transient hypoparathyroidism rate, higher median PTH levels 24 h after surgery and a lower postoperative PTH decline. We found no association between preoperative vitamin D and the development of protracted or permanent hypoparathyroidism.

Prognostic Involvement of Lymph Node Density in Oral Squamous Cell Carcinoma. A New Predictive Model

PURPOSE

Lymph node density (LND) has been reported to be a significant predictor of survival in oral squamous cell carcinoma (OSCC). The aim of this study was to analyze LND as a prognostic factor in OSCC and create a predictive model that determines the probability of death in these patients.

METHODS

A retrospective cohort study was carried out with a cohort of patients who underwent cervical dissection and primary resection of OSCC between 1980 and 2020. The primary predictor variable in this study was LND, which is defined as the number of positive lymph nodes divided by the total number of lymph nodes removed. The cutoff values for prediction of disease-specific survival (DSS) were calculated by receiver operating characteristic curve analysis, which determined the best cutoff value was 0.07. Patients were divided into binary subgroups (low and high risk) using the best cutoff value of LND. The outcome variable was DSS, defined as the duration from the date of diagnosis to death due to OSCC and not due to other causes or secondary tumors. Other variables were type of neck dissection, postsurgical treatment, surgical margin, pathological T category stage, pathological N category (pN) stage, extranodal extension, perineural invasion, bone invasion, and presence of recurrence. A predictive model (score) was generated by selecting variables using a log-rank test and by using the Cox proportional-hazards regression (multivariate analysis).

RESULTS

The sample consisted of 368 patients, 252 (68.5%) male and 116 (31.5%) female patients, with a mean age of 60.3 years. According to the LND cutoff value, there were 289 patients with a low LND (≤0.07) and 79 with a high LND (>0.07). The univariate analysis showed LND as a significant predictor of DSS at 5 years (67.1% in LND ≤ 0.07 vs 32.9% in LND > 0.07; P < .001). The Cox multivariate analysis identified LND (hazard ratio [HR] = 27.2; 95% confidence interval [CI], 3.18-231; P = .002), recurrence (HR = 4.45; 95% CI, 2.3-8.4; P < .001), and type of treatment (HR = 0.52; 95% CI, 0.34-0.81; P < .001) as independent predictive factors for DSS. In the predictive model, the presence of recurrence was the most important factor with 8 points, whereas LND >0.07 contributed only 1 point; however, the 2 categories resulting from this limit were statistically significant.

CONCLUSIONS

Our study demonstrates that LND is an additional prognostic factor in patients with a pN+ disease. In addition, our predictive model could be useful in the therapeutic algorithm of OSCC patients, as it can predict the probability of death in these patients.

Mohs Surgery Outside Usual Indications: A Review

The body of literature supporting the use of Mohs micrographic surgery (MMS) in tumors outside the main indications (basal cell carcinoma, squamous cell carcinoma, dermatofibrosacroma protuberans, lentigo maligna) is constantly growing, but it is still based on case reports, case series, or at best institutional case series that focus on a single malignancy. Our aim in this review was to assess use of MMS in an array of rare tumors outside the usual indications. A review was performed using the MEDLINE database and the search engine ClinicalKey®. We reviewed the use of MMS on atypical fibroxanthoma (AFX)/malignant fibrous histiocytoma, microcystic adnexal carcinoma, extramammary Paget's disease, Merkel cell carcinoma, pocrine/eccrine carcinoma/porocarcinoma, trichilemmal carcinoma, leiomyosarcoma, and angiosarcoma. Mohs micrographic surgery appears to be scarcely used in these tumors due to their low incidence. It is mainly performed for tumors in the H-zone of the face, and can be performed safely. The overall recurrence rate is lower compared with simple or wide local excision. MMS should be used in a more generalized fashion for these tumors.

Oral squamous cell carcinoma: epidemiological study and risk factor assessment based on a 39-year series

Oral squamous cell carcinoma (OSCC) remains a challenge for head and neck surgeons, with low 5-year survival rates despite improvements in diagnostic techniques and therapies. This retrospective observational study was performed to evaluate the epidemiology and risk factors in a cohort of 666 patients with invasive OSCC over a 39-year period. Risk factors assessed were age, sex, toxic habits, premalignant lesions, tumour location and size, and neck involvement, and pathological factors such as surgical margins, tumour thickness, perineural invasion, and bone invasion. These factors were analysed over time, and their influence on recurrence and survival rates examined. Results were compared with those of current epidemiological studies in the literature. This series showed a tendency to diagnosis at older ages (P<0.001) and decreased differences in sex distribution (P<0.001) over time. Regarding risk factors, tobacco and alcohol drinking increased significantly in females, but remained stable in males. Forty percent of the patients developed recurrences during follow-up; the relapse rate did not improve over time (45.6% in the 1980s to 36.1% in 2010-2017). The 5-year survival rate also remained stable over time, ranging from 62.7% (1980s) to 71.7% (2010-2017). This epidemiological study analysed trends across four decades in a stable cohort, with results that may be extrapolated to the populations of European countries. The results confirmed that recurrence rates and survival rates have not improved over time, despite better surgical treatments and new therapies. Further studies are needed to improve knowledge about genetics and tumour behaviour in oral cancer.