Proton Beam Therapy for HCC Exceeding up-to-Seven Criteria

PURPOSE/OBJECTIVE(S)

Whilst standard treatment for intermediate-stage hepatocellular carcinoma (HCC) is transcatheter arterial chemoembolization (TACE), those exceeding "up-to-seven" criteria don't respond as such as those within, and systemic therapy is suggested to be more beneficial. This is sought to be both because of the limited efficacy of TACE and its hepatic toxicity. Proton beam therapy (PBT) offers high local control and low toxicity rates, and we hypothesize that the same can be said in this patient group also. We here present the outcome of PBT for primary HCC exceeding "up-to-seven" criteria.

MATERIALS/METHODS

Primary HCC treated with PBT between 2010 and 2018 were extracted from an all-in treatment database and retrospectively reviewed. (Maximum diameter of the largest tumor in centimeters) + (tumor count) > 7 was considered as exceeding "up-to-seven" criteria. Local recurrence was defined as tumor re-enlargement or the appearance of arterial phase hyperenhancement. Adverse events were evaluated by CTCAE v5.0. Overall survival and recurrence-free survival were determined by the Kaplan-Meier method, and local recurrence was analyzed as cumulative incidence with death as a competing risk. All statistical analyses were done using R.

RESULTS

Out of 202 primary cases, 79 exceeded the "up-to-seven" criteria. The median tumor diameter was 8.0 cm (range 3.1 - 20 cm) and macroscopic vascular invasion (MVI) was observed in 26 cases. For tumor count, 36 were solitary, 28 were between 2 - 3, and 15 had 4 or more. According to the modified ALBI grade, 38 were grade 1, 18 were grade 2a and 23 were 2b. The prescribed dose was 66 Gy / 10 Fr for 6, 72.6 Gy / 22 Fr for 60, 74 Gy / 37 Fr for 12 and 60 Gy / 15 Fr for one case after relative biological effect weighting of 1.1. With a median follow-up period of 33 months (IQR 15 - 57 months), 2-year overall survival was 62% (95% C.I. 50 - 72%) and median survival time was 37 months (95% C.I. 30 - 52 months). 2-year recurrence-free survival and local recurrence rate were 42% (95% C.I. 30 - 53%) and 8% (95% C.I. 3 - 15%) respectively. Cox regression analysis revealed modified ALBI grade as the only significant risk factor for survival (hazard ratio 1.80, 95% C.I. 1.27 - 2.55, p = 0.0010) among age, sex, alpha-fetoprotein level, MVI, tumor count, and size. Other than one case of early death (2 weeks after treatment) with an unknown causal relationship, there were no adverse events of grade 4 or higher observed.

CONCLUSION

PBT for primary HCC exceeding "up-to-seven" criteria appears to be safe and effective. Local control of intrahepatic lesions may be beneficial even in intermediate-stage cases, while results of this study suggests that suppression of out-of-field recurrence is required for further survival prolongment.

The Japanese Nationwide Cohort Data of Particle Beam Therapy for Liver Oligometastasis in Esophagogastric Cancer Patients

PURPOSE/OBJECTIVE(S)

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology (JASTRO) in Japan in May 2016. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis of esophagogastric cancers.

MATERIALS/METHODS

Cases in which PBT was performed at all PBT facilities in Japan between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: controlled primary cancer; liver recurrence without extrahepatic tumors; and no more than three liver lesions. The dose and fraction of PBT were determined using unified treatment policy established by JASTRO. We used the following protocol, 64 gray (relative biological effect) (Gy (RBE))/8 fractions (fr) for the peripheral region, and 72.6 GyE/22fr for the central region. For safety aspect, the hepatocellular carcinoma irradiation protocols of 66 Gy (RBE)/10fr, 72.6-76 Gy (RBE)/20-22fr, and 74-76 Gy (RBE)/37-38fr could be allowed. The overall survival (OS), local control (LC), and adverse events (AEs) were examined. The OS and LC rates were calculated using the Kaplan-Meier method. Factors possibly related to OS, such as tumor size (for multiple lesions, the largest size), number of liver tumors, as well as the presence or absence of prior, concurrent, and post-PBT chemotherapy, were investigated. The cut-off values were estimated using the receiver operating characteristic curve and area under the curve. Univariate analysis was performed using the log-rank test. Statistical significance was P-values < 0.05.

RESULTS

Twenty-three males and two females with a median age of 69 (range, 52-80) years and 36 lesions were included. This study included six patients with esophageal and 19 patients with gastric cancer. The median lesion size, fraction size, and biological effective dose (BED)10 were 31 (7-104) mm, 3.8 gray (relative biological effect)/fractions (Gy (RBE)/fr) (2-8 Gy (RBE)/fr), and 96.9 (88.8-115.2) Gy, respectively. The median follow-up period was 18 (4-47) months. The 1-, 2-, and 3-year OS rates were 76.0, 49.5, and 43.3%, respectively, and the median OS was 19 months. The 1-, 2-, and 3-year OS rates of esophageal cancer were 83.3% for all. The 1-, 2-, and 3-year OS rates of gastric cancer were 73.7, 40.2, and 32.2%, respectively, and the median OS was 18 months. The 1-, 2-, and 3-year LC rates were 96.3, 91.5, and 91.5%, respectively. The 1-, 2-, and 3-year LC rates of esophageal cancer were 100% for all. The 1-, 2-, and 3-year LC rates of gastric cancers were 94.7, 88.0, and 88.0%, respectively. Tumor size was the only significant OS-related factor (P < 0.01). No grade 3 or higher adverse events were observed.

CONCLUSION

Owing to the low incidence of adverse events and the high LC rate, PBT is a feasible option for liver oligometastasis of esophagogastric cancers.

The Japanese Nationwide Cohort Data of Proton Beam Therapy for Liver Oligometastasis in Breast Cancer Patients

PURPOSE/OBJECTIVE(S)

A nationwide multicenter cohort study on particle therapy was launched by the Japanese Society for Radiation Oncology (JASTRO) in Japan. We analyzed the outcome of proton beam therapy (PBT) for liver oligometastasis in breast cancers.

MATERIALS/METHODS

Cases in which PBT was performed at all Japanese proton therapy facilities between May 2016 and February 2019 were enrolled. The patients were selected based on the following criteria: the primary cancer was controlled, liver recurrence without extrahepatic tumors, and no more than three liver lesions. The treatment indication and strategy were discussed at cancer boards in each institution. The dose and fraction of PBT were determined by referring to the unified treatment policy established by JASTRO. We used the following protocol: 64 gray (Gy) (relative biological effectiveness [RBE])/8 fraction (fr) for the hepatic periphery area away from the GI tract, and 72.6 GyE/22 fr for the adjacent hilar region type. Regarding safety, the HCC irradiation protocols of 66 GyE/10 fr, 72.6-76 GyE/20-22 fr, and 74-76 GyE/37-38 fr could be used. The local control (LC), overall survival (OS), and progression free survival (PFS) rates were calculated using the Kaplan-Meier method. Factors possibly related to OS, such as tumor size, number of liver tumors, intervention of chemotherapy, and/or hormone therapy, were investigated. The cut-off values were estimated using the receiver operating characteristic curve and area under the curve. Univariate analysis was performed using the log-rank test.

RESULTS

Fourteen females, with a median age of 57 (range, 44-73) years and twenty-two lesions were included. Nine patients had one lesion, two patients had two lesions, and three patients had three lesions. PBT was selected because nine patients had underlying disease and five patients had general conditions (age, etc.). The median lesion size, fraction size, and biological effective dose using the linear-quadratic model with α/β = 10 Gy ((BED)10) were 44 (20-130) mm, 6.6 (2-8) (relative biological effectiveness [RBE])/fraction (fr), and 109.6 (52.7-115.2) Gy, respectively. The median follow-up period of breast cancers was 22.8 (4-54) months. The 1-, 2-, and 3-year LC rates of liver metastasis from breast cancers were 100% for all. The 1-, 2-, and 3-year OS rates were 85.7%, 62.5%, and 62.5%, respectively. The 1-, 2-, and 3-year PFS rates were 50.0%, 33.3%, and 16.7%, respectively, and median PFS time was 16 months. Tumor size, the number of liver tumors, and the intervention of chemotherapy and/or hormone therapy at any time were not significantly related to the OS. Only one patient did not complete PBT due to current disease progression. The other patients completed PBT without interruption. One patient had grade 3 radiation-induced dermatitis.

CONCLUSION

Based on the low incidence of adverse events and the high LC rate, PBT appears to be a feasible option for liver oligometastasis in breast cancer patients.

Outcome of Proton Beam Therapy for Primary Hepatocellular Carcinoma with "Unfavorable" Macroscopic Classification

PURPOSE/OBJECTIVE(S)

Transcatheter arterial chemoembolization (TACE) is the standard treatment for early to intermediate-stage hepatocellular carcinoma (HCC) unfit for hepatectomy or radiofrequency/microwave ablation (RFA/MWA). Putting aside its hepatic toxicity, local control of TACE is far from satisfactory, especially with non- "simple nodular type" appearances, to an extent where systemic therapy is suggested to be more beneficial. We here analyzed the outcome of proton beam therapy (PBT) for primary HCC by macroscopic classification.

MATERIALS/METHODS

Primary HCC treated with PBT between 2010 and 2018 were extracted from an all-in treatment database. The macroscopic classification was defined by CT or MRI prior to PBT. Local recurrence was defined as tumor re-enlargement or the appearance of arterial phase hyperenhancement. Adverse events were evaluated by CTCAE v5.0. Overall survival, local control, intrahepatic recurrence-free survival, and extrahepatic recurrence-free survival were determined by the Kaplan-Meier method, and the association with treatment factors was analyzed by log-rank and cox regression model.

RESULTS

A total of 202 primary HCC cases were extracted, all not a candidate for hepatectomy nor RFA/MWA. Out of them, 75 cases were simple nodular type, 79 were simple nodular type with extranodular growth, 38 were confluent multinodular type, and 10 were infiltrative type. 26 cases were HBV positive, and 84 cases were HCV positive. 35 cases had macroscopic vascular invasion (MVI). With a median follow-up period of 3.72 years (IQR: 1.79-5.85years), the 3-year overall survival rate was 68.1% (95% CI 61.0 - 74.3%), the 3-year local control rate was 89.6% (95% CI 83.4-93.5), the 3-year intrahepatic recurrence-free survival rate was 53.7% (95% CI 45.9-60.8%), and the 3-year extrahepatic recurrence-free survival rate was 87.4% (95% CI: 81.5-91.6%). Simple nodular type had better overall survival (73.2% vs 65.2% p = 0.012) and extrahepatic recurrence free survival (96.9% vs 81.9% p<0.01), but there was no statistically significant difference in local control (92.7% vs 87.6% p = 0.06) and intrahepatic recurrence-free survival (62.0% vs 48.5% p = 0.114). Multivariate analysis of risk factors against OS, including age, sex, AFP, MVI, and macroscopic classification, revealed age and macroscopic classification as independent risk factors. Adverse events of grade 3 included 2 cases of gastrointestinal bleeding, 7 cases of liver function disorder, 1 cases of biliary hemorrhage, and 1 case of pleural effusion. Other than one case of early death (2 weeks after treatment) with an unknown causal relationship, there were no adverse events of grade 4 or severe.

CONCLUSION

PBT for non- "simple nodular type" primary HCC appears to be safe and effective, whilst suppression of out-of-field recurrence is needed for further survival prolongment.

[3H]thymidine autoradiographic and alkaline phosphatase histochemical studies of intestinal metaplasia of the human stomach

The relationship between cell proliferation and enzyme activity in intestinal metaplasia of the human stomach was studied using a combined method of [3H]thymidine autoradiography and alkaline phosphatase histochemistry on the same section. Three types of intestinal metaplasia were observed depending on variations in both enzymatic activity and isotope labelling. One type shows alkaline phosphatase-positive cells along the entire length of the glands with [3H]thymidine-labelled cells localized only at the bottom of the glands, resembling the duodenum. In another type of intestinal metaplasia, alkaline phosphatase-positive cells are present on the surface and/or upper half of the glands with mitotically active cells occupying the lower part of the glands. The third variety of intestinal metaplasia is characterized by the absence of alkaline-phosphatase activity and [3H]thymidine-labelled cells present in an extended zone in the lower half of the glands. Differences in labelling patterns of [3H]thymidine and the activity of marker enzyme in various types of intestinal metaplasia seem to reflect variations in cell differentiation during intestinalization of gastric mucosa.

Cytochemical localization of alkaline phosphatase in intestinal metaplasia of the human stomach

Alkaline phosphatase in the brush border of areas of intestinal metaplasia of human stomach was studied cytochemically. All absorptive cells in the upper part of the villi of the duodenum had strong alkaline phosphatase activity but, in areas of intestinal metaplasia, the metaplastic glands consisted of alkaline phosphatase-positive and negative absorptive cells. Alkaline phosphatase activity was found in tall dense microvilli of absorptive cells in areas of intestinal metaplasia and in the duodenum. However, in some areas of metaplastic epithelium the activity was very weak in some tall dense microvilli of absorptive cells but strong in those of neighbouring absorptive cells. No alkaline phosphatase activity was found in short sparse microvilli of absorptive cells in areas of intestinal metaplasia. The difference in alkaline phosphatase activity in microvilli of different cells in areas of intestinal metaplasia, which is not seen in the duodenum, indicates abnormal morphological and enzymatic differentiation intestinal metaplasia.

Distribution of marker enzymes and mucin in intestinal metaplasia in human stomach and relation to complete and incomplete types of intestinal metaplasia to minute gastric carcinomas

Intestinal metaplasia of the human stomach was classified into two types, complete and incomplete. The complete type was associated with the intestinal marker enzymes sucrose alpha-D-glucohydrolase, alpha, alpha-trehalase, aminopeptidase (microsomal) (APM), and alkaline phosphatase (ALP). Tissue of this type contained goblet cells and Paneth's cells but not high-iron diamine (HID)-positive mucin staining with HID-Alcian blue. The incomplete type of intestinal metaplasia was associated with sucrose alpha-D-glucohydrolase, APM, goblet cells, and HID-positive mucin but not with alpha, alpha-trehalase, ALP, or Paneth's cells. For the examination of the distribution of the complete and incomplete types in 84, 27, and 16 resected specimens of human stomach with gastric carcinoma, gastric ulcer, and duodenal ulcer, respectively, disaccharidases were located with Tes-Tape. Specimens with intestinal metaplasia were divided into three classes: complete type only (class I), incomplete type only (class II), and a mixture of areas of the complete and incomplete types (class III). Of the 84 specimens from patients with gastric carcinoma, intestinal metaplasia was found in 76 (01%), and the percentages of specimens of classes I, II, and III were 32, 22, and 46, respectively. In these specimens, the percent incidence of class I increased and that of class II decreased with age. Of the 27 specimens from patients with gastric ulcer, 16 (59%) shopwed intestinal metaplasia and 10 of the 16 (63%) specimens were of class II. Of the 16 specimens from patients with duodenal ulcer, only 3 (19%) specimens showed intestinal metaplasia and all of them were of class II. The relationships of the complete and incomplete types of intestinal metaplasia to gastric carcinoma wre studied in 26 foci of minute carcinoma of the stomach less than 5 mm in largest diameter. Nineteen of 20 (05%) foci of the intestinal type of minute carcinoma were surrounded by intestinal metaplasia and 16 foci (80%) were surrounded by the incomplete type of intestinal metaplasia.