Radiation-induced leiomyosarcoma of the prostate after brachytherapy for prostatic adenocarcinoma

Adjuvant brachytherapy for oral squamous cell carcinomas: a single-center experience comparing low-dose and pulsed-dose-rate techniques

OBJECTIVE

This study aims to assess the outcomes of adjuvant interstitial brachytherapy (BT) to the tumor bed for oral cavity squamous cell carcinoma (SCC), and to compare the oncological outcomes and toxicity profile of low-dose-rate (LDR) and pulsed-dose-rate (PDR) BT.

DESIGN

This retrospective single-center study included all patients who underwent postoperative LDR- or PDR-BT to the tumor bed as the sole adjuvant treatment for an oral tongue or floor of the mouth SCC between January 2000 and December 2020.

RESULTS

A total of 79 patients were eligible for this study. The cohort was divided into an LDR group (n = 38) and a PDR group (n = 41). The median time interval between surgery and brachytherapy was 55 days. Median delivered total dose was 55 Gy and median hospital stay was 5 days. Five patients (8.3%) experienced grade 3-4 early toxicity, 2 in the LDR group and 3 in the PDR group. Late toxicities were present in 28 patients (44.4%) and were dominated by grade 1-2 residual pain and dysesthesia, without a statistical difference between the groups. After a median follow-up of 65.1 months, 5‑year local control (LC), disease-free survival (DFS), and overall survival (OS) for the whole cohort were 76.3% (95% CI = 63.4-85.1), 61.6% (95% CI = 49.0-72.0), and 71.4% (95% CI = 58.6-80.8), respectively.

CONCLUSION

Adjuvant BT after excision of oral cavity SCC provides satisfactory oncological outcomes along with good tolerance. In our study, PDR-BT showed similar oncological and functional results to LDR-BT in this indication.

Assessment of Secondary Sarcomas Among Patients With Cancer of the Abdomen or Pelvis Who Received Combinations of Surgery, Radiation, and Chemotherapy vs Surgery Alone

IMPORTANCE

The association of radiation and chemotherapy with the development of secondary sarcoma is known, but the contemporary risk has not been well characterized for patients with cancers of the abdomen and pelvis.

OBJECTIVE

To compare the risk of secondary sarcoma among patients treated with combinations of surgery, radiation, or chemotherapy with patients treated with surgery alone and the general population.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study included 173 580 patients in Ontario, Canada, with nonmetastatic cancer of the prostate, bladder, colon, rectum or anus, cervix, uterus, or testis. Patients were enrolled from January 1, 2002, to January 31, 2017. Data analysis was conducted from March 1, 2019, to January 31, 2020.

EXPOSURES

Treatment combinations of radiation, chemotherapy, and surgery.

MAIN OUTCOME AND MEASURES

Diagnosis of sarcoma based on histologic codes from the Ontario Cancer Registry. Time to sarcoma was compared using a cause-specific proportional hazard model.

RESULTS

Of 173 580 patients, most were men (125 080 [72.1%]), and the largest group was aged between 60 and 69 years (58 346 [33.6%]). Most patients had genitourinary cancer (86 235 [51.4%]) or colorectal cancer (69 241 [39.9%]). Overall, 64 301 (37.1%) received surgery alone, 51 220 (29.5%) received radiation alone, 15 624 (9.0%) were treated with radiation and chemotherapy, 15 252 (8.8%) received radiation with surgery, and 11 822 (6.8%) received all 3 treatments. A total of 332 patients (0.2%) had sarcomas develop during a median (interquartile range) follow-up of 5.7 (2.2-8.9) years. The incidence of sarcoma was 0.3% among those who underwent radiation alone (138 of 51 220) and radiation with chemotherapy (40 of 15 624), 0.2% among those who received radiation and surgery (36 of 15 252) and all 3 modalities (25 of 11 822), and 0.1% among those who received surgery with chemotherapy (13 of 14 861) and surgery alone (80 of 64 801). Compared with a reference group of patients who had surgery alone, the greatest risk of sarcoma was found among patients who underwent a combination of radiation and chemotherapy (cause-specific relative hazard [csRH], 4.07; 95% CI, 2.75-6.01; P < .001), followed by patients who had radiation alone (csRH, 2.35; 95% CI, 1.77-3.12; P < .001), radiation with surgery (csRH, 2.33; 95% CI, 1.57-3.46; P < .001), and all 3 modalities (csRH, 2.27; 95% CI, 1.44-3.58; P < .001). In the general population, 7987 events occurred during 46 554 803 person-years (17.2 events per 100 000 person-years). The standardized incidence ratio for sarcoma among patients treated with radiation compared with the general population was 2.41 (95% CI, 1.57-3.69; 41.3 events per 100 000 person-years). The annual number of cases of sarcoma increased from 2009 (15 per 100 000 persons) to 2016 (32 per 100 000 persons), but the annual rate did not change during the study period.

CONCLUSIONS AND RELEVANCE

In this cohort study, patients treated with radiation or chemotherapy for abdominopelvic cancers had an increased rate of sarcoma. Although the absolute rate is low, patients and physicians should be aware of this increased risk of developing sarcoma.

Transanal total mesorectal excision for a large leiomyosarcoma at the lower rectum: a case report and literature review

BACKGROUND

Rectal leiomyosarcoma (LMS) is an extremely rare disease. Previously, LMS was not properly distinguishable from gastrointestinal stromal tumor (GIST) until c-kit, a characteristic marker of GIST, was discovered in 1998. No standard therapeutic strategy for gastrointestinal LMS has been established except for surgical resection because of its rarity. Rectal LMS is often accompanied by symptoms, which can enable detection at a small size. However, when a large LMS is detected at the lower rectum, it is difficult to excise due to the narrow pelvic space.

CASE PRESENTATION

We present the case of an 86-year-old man with a large LMS. The LMS was asymptomatic and incidentally found at the lower rectum when he visited another hospital for management of benign prostatic hypertrophy. An abdominoperineal resection of the rectum was performed with combined resection of both seminal vesicles and a part of the prostate because tumor invasion was suspected. We used the hybrid method of laparoscopic and transanal total mesorectal excision (TaTME) approaches to achieve negative surgical margins. Late-onset urethral injury occurred in the postoperative course, which was successfully treated with a urethral catheter. The patient was discharged and received no adjuvant therapy. Local recurrence did not occur, but multiple lung metastases were detected 4 months later and the patient died 12 months after the surgery.

CONCLUSIONS

This is the first report of the hybrid method of laparoscopic and TaTME approaches to remove a large LMS at the lower rectum.

miR-1207-3p regulates the androgen receptor in prostate cancer via FNDC1/fibronectin

Prostate cancer (PCa) is frequently diagnosed in men, and dysregulation of microRNAs is characteristic of many cancers. MicroRNA-1207-3p is encoded at the non-protein coding gene locus PVT1 on the 8q24 human chromosomal region, an established PCa susceptibility locus. However, the role of microRNA-1207-3p in PCa is unclear. We discovered that microRNA-1207-3p is significantly underexpressed in PCa cell lines in comparison to normal prostate epithelial cells. Increased expression of microRNA-1207-3p in PCa cells significantly inhibits proliferation, migration, and induces apoptosis via direct molecular targeting of FNDC1, a protein which contains a conserved protein domain of fibronectin (FN1). FNDC1, FN1, and the androgen receptor (AR) are significantly overexpressed in PCa cell lines and human PCa, and positively correlate with aggressive PCa. Prostate tumor FN1 expression in patients that experienced PCa-specific death is significantly higher than in patients that remained alive. Furthermore, FNDC1, FN1 and AR are concomitantly overexpressed in metastatic PCa. Consequently, these studies have revealed a novel microRNA-1207-3p/FNDC1/FN1/AR regulatory pathway in PCa.

A Review of the Literature on Primary Leiomyosarcoma of the Prostate Gland

Primary leiomyosarcoma of the prostate (PLSOP) is rare, with less than 200 cases reported so far. PLSOPs present with lower urinary tract symptoms, haematuria, and perineal pain; may or may not be associated with a history of previous treatment for adenocarcinoma of prostate by means of radiotherapy and or hormonal treatment; may afflict children and adult male. Examination may reveal benign enlarged prostate and hard enlarged mass. PLSOPs may be diagnosed by histological examination findings of spindle-shaped carcinoma cells in prostate specimens. Immunohistochemical staining tends to be positive for vimentin, CD44, smooth muscle actin, and calponin, focally positive for desmin, and at times positive for keratin. They stain negatively for PSA, S-100, CD34, CD117, and cytokeratin. Cytogenetic study on primary leiomyosarcoma of the prostate gland may show clonal chromosomal rearrangement involving Chromosomes 2, 3, 9, 11, and 19. On the whole the prognosis is poor. Surgery with or without chemotherapy would appear to be the mainstay of treatment for PLSOPs that are operable, but generally there is no consensus opinion on the best therapeutic approach. Most cases of PLSOPs are diagnosed in an advanced stage of the disease. A global multicenter trial is required to find therapies that would improve the prognosis.