Genomic Complexity Predicts Resistance to Endocrine Therapy and CDK4/6 Inhibition in Hormone Receptor-Positive (HR+)/HER2-Negative Metastatic Breast Cancer

PURPOSE

Clinical biomarkers to identify patients unlikely to benefit from CDK4/6 inhibition (CDK4/6i) in combination with endocrine therapy (ET) are lacking. We implemented a comprehensive circulating tumor DNA (ctDNA) analysis to identify genomic features for predicting and monitoring treatment resistance.

EXPERIMENTAL DESIGN

ctDNA was isolated from 216 plasma samples collected from 51 patients with hormone receptor-positive (HR+)/HER2-negative (HER2-) metastatic breast cancer (MBC) on a phase II trial of palbociclib combined with letrozole or fulvestrant (NCT03007979). Boosted whole-exome sequencing (WES) was performed at baseline and clinical progression to evaluate genomic alterations, mutational signatures, and blood tumor mutational burden (bTMB). Low-pass whole-genome sequencing was performed at baseline and serial timepoints to assess blood copy-number burden (bCNB).

RESULTS

High bTMB and bCNB were associated with lack of clinical benefit and significantly shorter progression-free survival (PFS) compared with patients with low bTMB or low bCNB (all P < 0.05). Dominant APOBEC signatures were detected at baseline exclusively in cases with high bTMB (5/13, 38.5%) versus low bTMB (0/37, 0%; P = 0.0006). Alterations in ESR1 were enriched in samples with high bTMB (P = 0.0005). There was a high correlation between bTMB determined by WES and bTMB determined using a 600-gene panel (R = 0.98). During serial monitoring, an increase in bCNB score preceded radiographic progression in 12 of 18 (66.7%) patients.

CONCLUSIONS

Genomic complexity detected by noninvasive profiling of bTMB and bCNB predicted poor outcomes in patients treated with ET and CDK4/6i and identified early disease progression before imaging. Novel treatment strategies including immunotherapy-based combinations should be investigated in this population.

[Effects of bariatric surgery on sex hormones in male patients with obesity]

Objective: To analyze and evaluate the differences in sex hormones after laparoscopic Roux-en-Y Gastric Bypass Surgery (LRYGB) and laparoscopic sleeve gastrectomy (LSG) in male patients with obesity. Methods: This study was a retrospective cohort study. The inclusion criteria were (1) male patients with obesity who met the surgical indications of the "Chinese Guidelines for Surgical Treatment of Obesity and Type 2 Diabetes" (2019 Edition); (2) patients with a body mass index (BMI) of ≥27.5 kg/m2 and obesity-related metabolic diseases, or patients with severe obesity and a BMI of ≥35 kg/m2; and (3) sex hormone levels checked 1 year after surgery. The exclusion criteria included (1) patients with endocrine diseases (thyrotoxicosis, hyperprolactinemia) and hypothalamic-pituitary lesions and (2) those with severe major organ dysfunction who could not tolerate anesthesia or surgery. According to the above criteria, the clinical data of male patients with obesity admitted to the Gastrointestinal Surgery/Bariatric Center of the First Affiliated Hospital of Jinan University from October 2017 to January 2020 were included. A total of 52 male patients with obesity were included in this study. The mean age, body weight, BMI, and total testosterone level were (29.3±10.2) years, (123.6±35.4) kg, (40.1±11.1) kg/m², and 7.6 (5.5, 9.1) nmol/L, respectively. Forty-five patients (86.5%) exhibited testosterone deficiency. Among all the patients, 29 underwent LSG (LSG group) and 23 underwent LRYGB surgery (LRYGB group). The main outcome measure was the change in sex hormone levels before and after bariatric surgery in all the patients. The secondary outcome measures were the comparison of changes in sex hormone levels before and after LSG and LRYGB. Results: Pearson correlation analysis showed that preoperative estradiol was positively correlated with waist circumference (R=0.299, P<0.05), hip circumference (R=0.326, P<0.05), and chest circumference (R=0.388, P<0.05). Testosterone was negatively correlated with BMI (R=-0.563, P<0.01), waist circumference (R=-0.521, P<0.01), hip circumference (R=-0.456, P<0.01), chest circumference (R=-0.600, P<0.01), and neck circumference (R=-0.547, P<0.01). One year following bariatric surgery, the serum testosterone (7.6 [5.5, 9.1] nmol/L vs. 13.6 [10.5, 15.4] nmol/L, Z=-5.910, P<0.001), follicle-stimulating hormone (4.7 [2.7, 5.3] IU/L vs. 6.5 [3.6, 7.8] IU/L, Z=-4.658, P<0.001), and progesterone (1.2 [0.4, 1.5] nmol/L vs. 1.9 [0.8, 1.3] nmol/L, Z=-2.542, P=0.011) levels were significantly higher in all the patients. Both estradiol (172.8 [115.6, 217.5] pmol/L vs. 138.3 [88.4, 168.1] pmol/L, Z=-2.828, P=0.005) and prolactin (11.4 [6.4, 14.6] mIU/L vs. 8.6 [4.8, 7.3] mIU/L, Z=-2.887, P=0.004) levels were decreased. In addition to prolactin levels in the LRYGB group, there were statistically significant differences in the levels of estradiol (P=0.030), follicle-stimulating hormone (P < 0.001), luteinizing hormone (P=0.033), progesterone (P=0.034), and testosterone (P<0.001) compared with their preoperative levels. In the LSG group, there were statistically significant differences in the levels of follicle-stimulating hormone (P=0.011), prolactin (P=0.023), and testosterone (P<0.001) compared with their preoperative levels. Conclusion: The degree of obesity in men was negatively correlated with testosterone levels. Both LRYGB and LSG can significantly improve sex hormone levels in male patients with obesity, and testosterone levels show a significant increase after surgery.

[Safety and feasibility of intrathoracic modified overlap esophagojejunostomy in laparoscopic radical resection of Siewert type Ⅱ adenocarcinoma of esophagogastric junction]

Objective: The study aimed to investigate the safety and feasibility of intrathoracic modified overlap method in laparoscopic radical resection of Siewert type II adenocarcinoma of the esophagogastric junction (AEG). Methods: A descriptive case series study was conducted. The clinical data of 27 patients with Siewert type II AEG who underwent transthoracic single-port assisted laparoscopic total gastrectomy and intrathoracic modified overlap esophagojejunostomy in Guangdong Provincial Hospital of Chinese Medicine from May 2017 to December 2020 were retrospectively analyzed. The intrathoracic modified overlap esophagojejunostomy was performed as follows: (1) The Roux-en-Y loop was made; (2) The jejunum side was prepared extraperitoneal for overlap anastomosis; (3) The esophagus side was prepared intraperitoneal for overlap anastomosis; (4) The overlap esophagojejunostomy was performed; (5) The common outlet was closed after confirmation of anastomosis integrity without bleeding; (6) A thoracic drainage tube was inserted into the thoracic hole with the diaphragm incision closed. The intraoperative and postoperative results were reviewed. Results: All 27 patients were successfully operated, without mortality or conversion to laparotomy. The operative time, digestive tract reconstruction time and esophageal-jejunal anastomosis time were (327.5±102.0) minute, 50 (28-62) minute and (29.0±7.4) minute, respectively. The blood loss was 100 (20-150) ml. The postoperative time to flatus and postoperative hospital stay were (4.7±3.7) days and 9(6-73) days, respectively. Three patients (11.1%) developed postoperative grade III complications according to the Clavien-Dindo classification, including 1 case of anastomotic fistula with empyema, 1 case of pleural effusion and 1 case of pancreatic fistula, all of whom were cured by puncture drainage and anti-infective therapy. Conclusions: The intrathoracic modified overlap esophagojejunostomy is safe and feasible in laparoscopic radical resection of Siewert type II AEG.

[Five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection for Siewert type Ⅱ adenocarcinoma of the esophagogastric junction]

Objective: Surgical operation is the main treatment for advanced adenocarcinoma of esophagogastric junction (AEG). Due to its special anatomic location and unique lymph node reflux mode, the surgical treatment of Siewert II AEG is controversial. Lower mediastinal lymph node dissection is one of the most controversial points and a standard technique has not yet been established. This study is aim to explore the safety and feasibility of five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection for Siewert type II AEG. Methods: A descriptive case series study was conducted. The intraoperative and postoperative data of 25 patients with Siewert type II AEG who underwent five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection in Guangdong Provincial Hospital of Traditional Chinese Medicine from January 2019 to April 2021 were retrospectively analyzed. Five-step maneuver was as follows: In the first step, the subcardiac sac was exposed; the right pulmonary ligament lymph nodes and the anterior thoracic paraaortic lymph nodes were dissected cranial to inferior pericardium, left to left edge of thoracic aorta. In the second step, the left diaphragm was opened, and a 12 mm trocar was placed through the 6-7 rib in the left anterior axillary line. The supra-diaphragmatic nodes were dissected through the thoracic operation hole. In the third step, the left inferior pulmonary ligament was severed. The anterior fascia of thoracic aorta was incised to join the anterior space of thoracic aorta formed in the first step and then the lymphatic tissue was dissected upward until the exposure of left inferior pulmonary vein. In the fourth step, the posterior pericardium was denuded retrogradely from ventral side to oral side to the level of left inferior pulmonary vein, right to right pleura, and then the right pulmonary ligament lymph nodes were completely removed. In the fifth step, the esophagus was denuded, and the esophagus was transected 5 cm above the tumor using a linear stapler to complete the dissection of lower thoracic paraesophageal lymph nodes. Results: Operations were successfully completed in 25 patients without conversion, intra-operative complication and perioperative death. Total gastrectomy was performed in 19 cases and proximal gastrectomy in 6 cases. The mean operative time was (268.7±85.6) minutes, the mean estimated blood loss was (90.4±44.2) ml, the mean time of lower mediastinal lymph node dissection was (38.6±10.3) minutes, and the mean harvested number of lower mediastinal lymph node was 5.9±2.9. The length of esophageal invasion was >2 cm in 7 cases and ≤ 2 cm in 18 cases. Eight patients (33.0%) had lower mediastinal lymph node metastasis, including 3 cases with esophageal invasion >2 cm and 5 cases with esophageal invasion ≤ 2 cm. The mean time to postoperative first flatus was (5.5±3.1) days. The average time of postoperative thoracic drainage was (5.9±2.9) days. The mean hospital stay was (9.7±3.1) days. Two patients (8.0%) developed postoperative grade IIIa complications according to the Clavien-Dindo classification, including 1 case of pancreatic fistula and 1 case of pleural effusion, both of whom were cured by puncture drainage. Conclusions: Five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph nodes dissection for Siewert type II AEG is safe and feasible. Which can ensure sufficient lower mediastinal lymph node dissection to the level of left inferior pulmonary vein.

[Efficacy observation of the caudal-medial approach combined with "page-turning" middle lymphadenectomy in the laparoscopic right hemicolectomy]

Objective: To investigate the safety and feasibility of caudal-medial approach combined with "page-turning" middle lymphadenectomy in the laparoscopic right hemicolectomy. Methods: A descriptive cohort study was conducted. Clinical data of 35 patients who underwent laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy at Department of Gastrointestinal Surgery, Guangdong Hospital of Chinese Medicine from April 2018 to May 2020 were retrospectively analyzed. All operations were performed consecutively by the same surgeon. The caudal-medial approach was used to dissect the right Toldt's fascia and the anterior pancreaticoduodenal space in a caudal-to-cranial and medial-to-lateral manner guided by the duodenum. The "page-turning" middle lymphadenectomy was used to dissect the mesocolon along the superior mesenteric vein with ileocolic vein, Henle's trunk and pancreas exposed preferentially. Results: All the 35 patients completed the operation successfully, and there was no damage and bleeding of superior mesenteric vessels and their branches. The operative time was (186.9±46.2) minutes, and the blood loss was 50 (10-200) ml. The first time to flatus was (2.1±0.6) days, and the time to fluid intake was (2.5±0.8) days. The postoperative hospital stay was 6 (3-18) d. The overall morbidity of postoperative complication was 8.6% (3/35), including grade II in 1 cases (2.8%) and grade IIIa in 2 case (5.7%) according to the Clavien-Dindo grading standard. The total number of lymph node dissected was 30.2±5.6, and the positive lymph node was 0 (0-7). Tumor staging revealed 5 cases of stage I, 18 cases of stage II, 11 cases of stage III, and 1 case of stage IVA. In this study, the median follow-up time was 15 (4-29) months. One patient died due to cerebrovascular accident 12 months after surgery, and no tumor recurrence or metastasis was observed in all other patients. Conclusions: Laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy is safe and feasible. The anterior pancreaticoduodenal space is preferentially mobilized, which reduces the difficulty of central vascular dissection.

Ferroelectricity and ferromagnetism of La(0.5)Lu(0.5)Ni(0.5)Mn(0.5)O(3) thin films on Nb:SrTiO(3) substrates

Epitaxial orthorhombic La(0.5)Lu(0.5)Ni(0.5)Mn(0.5)O(3) (LLNMO) thin films deposited on Nb:SrTiO(3) (NSTO) substrates are prepared by pulsed laser deposition and their ferroelectricity and magnetism are investigated using various techniques. It is revealed that the as-prepared thin films are ferromagnetic (FM) insulators. The FM transition occurring at ∼ 125 K is evidenced by the well defined hysteresis at low temperature, with a saturated magnetic moment as high as 1.8 µ(B)/f.u. at ∼ 5 K. A reversible ferroelectric polarization of ∼ 0.2 µC cm(-2) below ∼ 140 K is also observed. The magnetism can be understood by the FM ordering associated with a partially ordered major Ni(2 +)-Mn(4 +) plus minor Mn(3+)-Ni(3+) configuration, while the ferroelectricity is argued to originate from the A-site disordering of La(3+) and Lu(3+).

Competition between quantum fluctuations and antiferroelectric order in Ru-doped Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3)

The competition between quantum fluctuations and the antiferroelectric state in Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3) is investigated by measuring the low-temperature dielectric permittivity and by Raman spectroscopy. We demonstrate the significant impact of quantum fluctuations on the stability of the antiferroelectric polar order. It is revealed that the structural phase transitions can be modified by the quantum fluctuations, enhancing the stability of the high-symmetry phase and suppressing the antiferroelectric transitions. More importantly, a quantum antiferroelectric state, exhibiting similar behavior as the quantum ferroelectric state in terms of dielectric response, is identified. In addition, the effect of quantum fluctuations on the increasing permittivity at low temperature is also discussed.

Expressions of IGF-1 and TGF-beta 1 in the condylar cartilages of rapidly growing rats

OBJECTIVE

This study was designed to investigate the expressions of IGF-I and TGF-beta 1 in condyles and to determine if the special modeling and remodeling of the condylar cartilages are regulated by growth factors.

METHODS

Fifty 5-weeks-old male rats were assigned to five groups randomly, and one group was sacrificed every week. The condyles were harvested from rats whose ages ranged from 5- to 9-weeks-old and they were inspected by using S-P immunocytochemical techniques.

RESULTS

IGF-I and TGF-beta 1 are expressed during condylar cartilage development in a temporally and spatially regulated fashion, and different growth factors have different expressing characteristics. The expressions of IGF-I are more intense in germinal and transitional layers, while TGF-beta 1 expression was high in the mature and degenerated layers. In germinal and transitional layers, IGF-I expression was high at the beginning of rapid growth, while TGF-beta 1 expression was low. At the end of the rapid growth, IGF-I expression was lower and TGF-beta 1 expression was still high. In the mature and degenerated layers, TGF-beta 1 expression was very high, while IGF-I expression was lower throughout rapid growth.

CONCLUSIONS

The growth factors are expressed differentially, and each shows specific or overlapping localization patterns depending on the stage of developmental process, meaning that IGF-I and TGF-beta 1 may regulate condylar cartilage proliferation and differentiation in an interrelated system. This study suggests that growth factors can be produced locally by condylar cartilages and play an important role in the metabolism of condylar cartilages.

[Clinical application of the Begg light wire technique]

The authors analysed the typical malocclusion cases treated by Begg light wire technique and discussed the following questions: 1. Case selection: should pay great attention to the maxillofacial growth pattern, differentiate the type of deformities, dental or skeletal. 2. The overbite cases were corrected chiefly by incisor intrusion and molar extrusion. 3. The effect of intermaxillary elastics to anchorage teeth and movement teeth was evaluated. 4. Problems and solutions in all treatment stages, advantages and disadvantages of Begg technique were all discussed.

A retrospective cohort study of leukemia and other cancers in benzene workers

A retrospective cohort study was carried out in 1982-1983 among 28,460 benzene-exposed workers (15,643 males, 12,817 females) from 233 factories and 28,257 control workers (16,621 males, 12,366 females) from 83 factories in 12 large cities in China. All-cause mortality was significantly higher among the exposed (265.46/100,000 person-years) than among the unexposed (139.06/100,000 person-years), as was mortality from all malignant neoplasms (123.21/100,000 versus 54.7/100,000, respectively). For certain cancers, increased mortality was noted among benzene-exposed males in comparison with that among unexposed males; the standardized mortality ratios (SMR) were elevated for leukemia (SMR = 5.74), lung cancer (SMR = 2.31), primary hepatocarcinoma (SMR = 1.12), and stomach cancer (SMR = 1.22). For females only leukemia occurred in excess among the exposed. Risk of leukemia rose as duration to exposure to benzene increased up to 15 years, and then declined with additional years of exposure. Leukemia occurred among some workers with as little as 6 to 10 ppm average exposure and 50 ppm-years (or possibly less) cumulative lifetime exposure (based on all available measurements for the exposed work units). Among the 30 leukemia cases identified in the exposed cohort, the proportion of subjects with acute lymphocytic leukemia was substantially lower and the proportion with acute nonlymphocytic leukemias was higher than in the general population. During 1972 to 1981, the annual incidence of leukemia ranged from 5.83 to 28.33 per 100,000 with higher rates occurring in the interval 1977 to 1981 than in the earlier years of the study period.(ABSTRACT TRUNCATED AT 250 WORDS)

Leukaemia in benzene workers: a retrospective cohort study

A retrospective cohort study was conducted in 233 benzene factories and 83 control factories in 12 cities in China. The benzene cohort and the control cohort consisted of 28,460 benzene exposed workers (178,556 person-years in 1972-81) and 28,257 control workers (199,201 person-years). Thirty cases of leukaemia (25 dead and 5 alive) were detected in the former and four cases (all dead) in the latter. The leukaemia mortality rate was 14/100,000 person-years in the benzene cohort and 2/100,000 person-years in the control cohort; the standardized mortality ratio was 5.74 (p less than 0.01 by U test). The average latency of benzene leukaemia was 11.4 years. Most (76.6%) cases of benzene leukaemia were of the acute type. The mortality due to benzene leukaemia was high in organic synthesis plants followed by painting and rubber synthesis industries. The concentration of benzene to which patients with a leukaemia were exposed ranged from 10 to 1000 mg/m3 (mostly from 50 to 500 mg/m3). Of the 25 cases of leukaemia, seven had a history of chronic benzene poisoning before the leukaemia developed.

Repair of severe tissue loss and deformity of maxillofacial area

Our experience in the management of 125 patients with massive facial defects since 1975 is detailed. The defects were closed in one of four principal ways (or a combination thereof): (1) free flap, (2) musculocutaneous flap, (3) forehead flap, and (4) dorsal tube flap. The surgical details and indications for each of these are outlined and examples given.