Analysis of reoperational reason of patients with thyroid cancer and strategies for its diagnosis and treatment: A 6-year single-center retrospective study

The incidence of thyroid tumors has been increasing in recent years, and the vast majority of new malignant cases are papillary thyroid micro-carcinoma (PTMC).¹ For patients with PTMC, comprehensive diagnosis and treatment, led by surgery, is the key to clinical cure. Although the lethality of papillary thyroid carcinoma is very low, tumor proliferation mechanism and surgical method after recurrence are still a hot topic of debate.^2-4 In this paper, thyroid patients admitted from January 2015 to December 2020 were collected. The inclusion criteria were as follows: (1) age from 18 to 80 years old; (2) the first and subsequent surgeries for thyroid were performed in one single center; (3) the postoperative paraffin pathology confirmed thyroid tumor; and (4) the patient's clinical data were complete. In this study, the gender, age, surgical methods, tumor types, maximum diameter of tumor, metastasis of central neck group and lateral lymph nodes, postoperative complications, and length of hospital stay were collected and recorded. For patients with multiple surgeries, the reason for subsequent surgeries and the interval time between surgeries should be additionally recorded.

A total of 58 patients undergoing thyroid surgeries (1 patient with laparoscopic surgery was excluded) were collected in this study, as shown in Table 1. Fifteen patients in the observation group underwent central lymph node dissection and 26 patients in the lateral lymph node dissection, while only 1 patient in the control group underwent cervical lateral lymph node dissection, and there was a statistically significant difference in the overall surgical method between the two groups (p < 0.01).

In the control group, 4 cases of benign tumors and 21 cases of papillary carcinoma were confirmed by pathology after the surgery. However, 55 cases of postoperative pathology confirmed malignant tumors in the observation group, including 52 cases of papillary carcinoma, 2 cases of follicular carcinoma, and 1 case of medullary carcinoma. In patients with confirmed papillary carcinoma, the mean tumor size was 1.33 ± 0.14 cm (p < 0.001). The rate of lymph node metastasis in the central group was 27 out of 118 (p < 0.0001) and the rate of lateral lymph node metastasis was 162 out of 241 (p < 0.01), as shown in Table 1.

The average length of hospital stay in the observation group was 5.64 ± 0.30 days (p < 0.05). There were five cases of adverse reactions (p > 0.05) after the operation, including four cases of hoarseness, one case of choking cough (with hoarseness), and one case of hemorrhage. The average length of hospitalization in the control group was 4.44 ± 0.38 days, and no patients had obvious adverse reactions (Table S1).

Out of 58 patients who underwent multiple surgeries, 51 patients underwent two surgeries, and 7 patients underwent three surgeries. Among the patients undergoing the second operation, 14 cases were planned surgery, of which 4 cases underwent total thyroidectomy for specific malignant tumors (2 cases of thyroid follicular carcinoma, 1 case of medullary thyroid carcinoma, 1 case of parathyroid carcinoma), and 10 cases of secondary surgery were performed within a limited time due to the large size of the tumor compressing the trachea or the tumor invading the peripheral nerves. Another 44 cases were unplanned surgeries (tumor recurrence was considered, but 3 of them did not find a malignant basis for postoperative paraffin pathology). The surgical indications for the third surgery patients were lymph node dissection, and the postoperative pathology confirmed cervical lymph node metastasis.

Surgical is currently the most common treatment for thyroid cancer, and surgical complications are closely related to the surgical method. Through nearly 6 years of retrospective research, this research suggests that, for patients with thyroid nodules, the main indication for surgery is tumor recurrence, followed by planned surgery (staging surgery is mainly selected because of the possibility of tumor invasion of nerve or tracheal compression, and a small number of residual thyroidectomies is performed for special malignant tumors). A recent study suggests that thyroid cancer in men has an older age of onset and a later stage and more aggressiveness,⁵ which is consistent with our study, which showed an increase in the proportion of male patients undergoing secondary surgery (but no statistical difference). For patients undergoing the second and third surgeries of thyroid, the average interval between operations was 13.41 ± 1.85 and 22.14 ± 4.61 days (Table S1), and the common procedures were total thyroidectomy, cervical central lymph node dissection, and cervical lateral lymph node dissection.

Compared with a single thyroid surgery, the rate of lymph node metastasis (first-time postoperative pathology) was significantly higher in patients with reoperation, which also suggested a late stage of malignancy, which was consistent with the results of reoperation confirming lymph node metastasis. However, there were no significant statistical differences in the average length of hospital stay, postoperative adverse reactions, central lymph node metastasis rate, and lateral lymph node metastasis in the second-surgery patients compared with the first-surgery patients. Therefore, for thyroid patients with a greater risk of surgery, this study suggests that a second operation can be performed within a limited time to avoid unnecessary surgical trauma. In view of the fact that this study is a single-center retrospective study, and considering the slow progression characteristics of PTC, the above conclusions need to be confirmed by a long-term study with a large number of multicenter samples.

Rongli Xie: Conceptualization (lead); data curation (lead); formal analysis (lead); funding acquisition (lead); investigation (lead); methodology (lead); resources (lead); software (lead); supervision (lead); validation (lead); writing—original draft (lead); writing—review and editing (lead). Yawei Feng: Writing—original draft (lead). Jiankang Shen: Writing—original draft (lead). Guohui Xiao: Conceptualization (equal); data curation (equal); formal analysis (equal); funding acquisition (equal); investigation (equal); methodology (equal); project administration (equal); resources (equal); software (equal); supervision (equal); validation (equal); writing—original draft (lead); writing—review and editing (lead). Dan Tan: Conceptualization (equal); data curation (equal); formal analysis (equal); funding acquisition (equal); investigation (equal); methodology (equal); project administration (equal); resources (equal); software (equal); supervision (equal); validation (equal); writing—original draft (lead); writing—review and editing (lead). All authors have read and approved the final manuscript.

The authors declare no conflicts of interest.

This retrospective study was approved by the Ethics Committee of Ruijin Hospital Lu Wan Branch (LWEC2022009). All the procedures were implemented based on the principles of the Declaration of Helsinki. Since this is a retrospective research and anonymized data were evaluated, patient consent was waived by our institutional ethics committee.