Variants in the GPR146 Gene Are Associated With a Favorable Cardiometabolic Risk Profile

BACKGROUND

In mice, GPR146 (G-protein-coupled receptor 146) deficiency reduces plasma lipids and protects against atherosclerosis. Whether these findings translate to humans is unknown.

METHODS

Common and rare genetic variants in the GPR146 gene locus were used as research instruments in the UK Biobank. The Lifelines, The Copenhagen-City Heart Study, and a cohort of individuals with familial hypobetalipoproteinemia were used to find and study rare GPR146 variants.

RESULTS

In the UK Biobank, carriers of the common rs2362529-C allele present with lower low-density lipoprotein cholesterol, apo (apolipoprotein) B, high-density lipoprotein cholesterol, apoAI, CRP (C-reactive protein), and plasma liver enzymes compared with noncarriers. Carriers of the common rs1997243-G allele, associated with higher GPR146 expression, present with the exact opposite phenotype. The associations with plasma lipids of the above alleles are allele dose-dependent. Heterozygote carriers of a rare coding variant (p.Pro62Leu; n=2615), predicted to be damaging, show a stronger reductions in the above parameters compared with carriers of the common rs2362529-C allele. The p.Pro62Leu variant is furthermore shown to segregate with low low-density lipoprotein cholesterol in a family with familial hypobetalipoproteinemia. Compared with controls, carriers of the common rs2362529-C allele show a marginally reduced risk of coronary artery disease (P=0.03) concomitant with a small effect size on low-density lipoprotein cholesterol (average decrease of 2.24 mg/dL in homozygotes) of this variant. Finally, mendelian randomization analyses suggest a causal relationship between GPR146 gene expression and plasma lipid and liver enzyme levels.

CONCLUSIONS

This study shows that carriers of new genetic GPR146 variants have a beneficial cardiometabolic risk profile, but it remains to be shown whether genetic or pharmaceutical inhibition of GPR146 protects against atherosclerosis in humans.

Fibromatosis of the neck causing airway obstruction managed effectively with weekly low-dose methotrexate and vinblastine

Fibromatosis is a rare disease with benign histology. Its infiltrative growth pattern may prevent complete resection. We report a case of a 40-year-old woman with fibromatosis of the neck requiring an emergency operation for acute upper airway obstruction. Gross residual tumour was left behind but excellent tumour shrinkage was achieved by using weekly low-dose methotrexate and vinblastine. Despite the use of newer agents such as imatinib, cytotoxic chemotherapy remains an efficacious treatment for inoperable fibromatosis.

Evaluation of the prognostic value of 2005 St Gallen risk categories for operated breast cancers in Hong Kong

Incorporating various new and conventional risk factors, the 2005 St Gallen risk categorization is a potentially useful prognostic tool for breast cancers. We conducted a retrospective study to evaluate its application in Hong Kong. Of the 902 included female breast cancers with median follow-up of 5.4 years, 7%, 63% and 30% patients were classified as low-, intermediate- and high-risk categories, respectively. Their corresponding 5-year distant disease-free survivals (DDFS) were 100%, 92% and 72%, respectively (p<0.00005). In the intermediate-risk category, node-positive patients had marginally inferior 5-year DDFS than node-negative patients (89% vs. 93%, p=0.0551). In the high-risk category, patients having HER2 overexpressed tumors and 1-3 positive nodes had significantly better DDFS than other patients with > or = 4 positive nodes (89% vs. 65%, p=0.0001). Overall, the 2005 St Gallen risk categorization had high prognostic value. However, the impact of HER2 overexpression might be affected by reproducibility of HER2 tests.

Breast conservation treatment in Hong Kong-early results of 203 patients: retrospective study

OBJECTIVE

To study the clinical outcomes of patients with invasive or non-invasive breast cancer after breast conservation treatment.

DESIGN

Retrospective study.

SETTING

Clinical oncology department of a public hospital, Hong Kong.

PATIENTS

Two hundred and three patients who received postlumpectomy radiotherapy at the Pamela Youde Nethersole Eastern Hospital between January 1994 and June 1999.

INTERVENTIONS

Adjuvant radiotherapy with or without systemic adjuvant treatment.

MAIN OUTCOME MEASURES

Actuarial local control rate, progression-free survival rate, disease-specific survival rate, and cosmetic score.

RESULTS

The median follow-up was 3.5 years. Two of the 25 patients with carcinoma in situ only developed local recurrence; the 5-year actuarial local control rate was 91.3%. Among the 178 patients with invasive cancer, seven had a local recurrence and 12 developed distant metastases without local failure. The 5-year actuarial local control, progression-free survival, and disease-specific survival rates for patients with invasive cancer were 95.5%, 85.8%, and 95.2%, respectively. The risk of local recurrence was significantly increased for younger patients (age <40 years) and those with positive final margins. Cosmetic scores were rated good to excellent by 95.6% of patients.

CONCLUSIONS

The early clinical outcomes of these patients are comparable to those in large overseas trials, which have demonstrated the equivalence of mastectomy and breast conservation treatment in terms of survival. In addition to mastectomy, with or without breast reconstruction, breast conservation treatment should be offered as an alternative to suitable Chinese women. To maximise local control, further excision or mastectomy is recommended for patients with positive final margins.

Metastatic tumour of the tunica vaginalis testis from carcinoma of the stomach

A 50-year-old man with advanced inoperable gastric adenocarcinoma and diffuse peritoneal metastasis received six cycles of palliative chemotherapy and responded clinically with weight gain. Two months after the completion of chemotherapy, however, he developed a left hydrocele. Aspiration yielded 70 ml of yellowish hydrocele fluid, which contained metastatic adenocarcinoma cells, consistent with a gastric primary tumour. A diagnosis of malignant hydrocele was made. Two weeks later, he developed a painful recurrent left hydrocele with increasing pain and swelling. Left orchidectomy was performed. Tiny white mural nodules measuring 1 mm in size were noted on the tunica vaginalis. No focal lesion was noted in the testis. On microscopic examination, the tunica vaginalis showed reactive mesothelial hyperplasia and extensive lymphatic permeation by poorly differentiated adenocarcinoma, consistent with a gastric primary tumour.

Quadruple primary neoplasms in a 27-year-old woman

A27-year-old woman was referred to our department on 3 February 1998 with a diagnosis of malignant melanoma associated with cystic teratoma of ovary. She had had a laparotomy and bilateral salphingo-oophorectomy on 5 January 1998. Pathology revealed tumour involvement of left ovary, left parametrium and malignant ascites, the right ovary showed polycystic disease, the uterus showed simple hyperplasia of endothelium, the omentum had no tumour and subdiaphragmatic scrapping was negative. On histological examination of the tumour, the cystic portion was basically a cystic teratoma with presence of skin, glial and bony tissue, the solid portion consisted of sheets of undifferentiated tumour cells, which on immunohistochemical staining shown strong positivity to HMB 45 and S-100. Ultrastructual examination confirmed melanocytic differentiation.

Her chest X-ray was clear. Computed tomography of abdomen and pelvis suggested bilobar liver metastasis and significant para-aortic lymphadenopathy. The alpha-fetoprotein (αFP) and beta-human chorionic gonadotrophin (β-hCG) were within normal limits. The diagnosis was a malignant melanoma arising in cystic teratoma of ovary, stage IV disease.

Her past medical history included multiple primary neoplasms. She had right thigh cutaneous histiocytoma at the age of 20 years, with complete excision performed. She developed poorly differentiated invasive ductal carcinoma of left breast (stage pT2N0M0) at the age of 21 years and had a left mastectomy and left axillary clearance; no postoperative adjuvant treatment was given. She also recently had multiple thyroid nodules which shown atypical cells, suggestive of a follicular neoplasm, and total thyroidectomy was contemplated.

Evaluation of her family revealed a strong family history of malignancy. Her twin sister died of a primary brain tumour at the age of 8 years. Her father died of lung cancer at the age of 45 years. Her paternal grandfather died of lung cancer in his 60s. Her paternal grandmother died of primary liver cancer in her 60s. One of her paternal half-uncles (mutual grandfather, different grandmothers) died of a primary brain tumour in his 50s while another died of lung cancer in his 70s. There was no positive family history of malignancy on her maternal side (Figure 1).

She was treated with combination chemotherapy using cisplatin (75 mg/m2) and cyclophosphamide (750 mg/m2). However, she deteriorated rapidly after the first cycle of chemotherapy and died on 16 March 1998.