Skye Hongiun Cheng

Gene expression predictors of breast cancer outcomes

BACKGROUND Correlation of risk factors with genomic data promises to provide specific treatment for individual patients, and needs interpretation of complex, multivariate patterns in gene expression data, as well as assessment of their ability to improve clinical predictions. We aimed to predict nodal metastatic states and relapse for breast cancer patients. METHODS We analysed DNA microarray data from samples of primary breast tumours, using non-linear statistical analyses to assess multiple patterns of interactions of groups of genes that have predictive value for the individual patient, with respect to lymph node metastasis and cancer recurrence. FINDINGS We identified aggregate patterns of gene expression (metagenes) that associate with lymph node status and recurrence, and that are capable of predicting outcomes in individual patients with about 90% accuracy. The metagenes defined distinct groups of genes, suggesting different biological processes underlying these two characteristics of breast cancer. Initial external validation came from similarly accurate predictions of nodal status of a small sample in a distinct population. INTERPRETATION Multiple aggregate measures of profiles of gene expression define valuable predictive associations with lymph node metastasis and disease recurrence for individual patients. Gene expression data have the potential to aid accurate, individualised, prognosis. Importantly, these data are assessed in terms of precise numerical predictions, with ranges of probabilities of outcome. Precise and statistically valid assessments of risks specific for patients, will ultimately be of most value to clinicians faced with treatment decisions.

Local radiotherapy with or without transcatheter arterial chemoembolization for patients with unresectable hepatocellular carcinoma

PURPOSE To evaluate the treatment outcome, patterns of failure, and prognostic factors for patients with unresectable hepatocellular carcinoma (HCC) treated with local radiotherapy alone or as an adjunct to transcatheter arterial chemoembolization (TACE). METHODS AND MATERIALS From March 1994 to December 1997, 25 patients with unresectable HCC underwent local radiotherapy to a portion of the liver. Twenty-three patients were classified as having cirrhosis in Child-Pugh class A and 2 in class B. Mean diameter of the treated hepatic tumor was 10.3 cm. Mean dose of radiation was 46.9 +/- 5.9 Gy in a daily fraction of 1.8-2 Gy. Sixteen patients were also treated with Lipiodol and chemotherapeutic agents mixed with Ivalon or Gelfoam particles for chemoembolization, either before and/or after radiotherapy. Percutaneous ethanol injection therapy (PEIT) was given to one patient. All patients were monitored for treatment-related toxicity and for survival and patterns of failure. RESULTS In a median follow-up period of 23 months, 11 patients were alive and 14 dead. The median survival duration from treatment was 19.2 months with a 2-year survival of 41%. Only 3 of 25 patients had local progression of the treated hepatic tumor. The recurrences were seen within the liver or extrahepatic. The 2-year local, regional, and extrahepatic progression-free survival rates were 78%, 46%, and 39%, respectively. The local control ranked the highest. Patients with Okuda Stage I disease had significantly longer survival than those with Stage II and III (p = 0.02). Patients with T4 disease (p = 0.02) or treated with radiotherapy alone (p = 0.003) had significantly shorter survival. T4 disease (p = 0.03) and pretreatment alpha-fetoprotein level of more than 200 ng/ml (p = 0. 03) were associated with significantly worse regional progression-free survival. A significant difference was observed in both regional progression-free survival (p = 0.0001) and extrahepatic progression-free survival (p = 0.005) between patients with and without portal vein thrombosis before treatment. The presence of satellite nodules had a significantly worse impact on regional progression-free survival (p = 0.04) and extrahepatic progression-free survival (p = 0.03). Patients with hepatic tumor more than 6 cm in diameter or portal vein thrombosis tended to have shorter survival. Radiation-induced liver disease (RILD) and gastrointestinal bleeding were the most common treatment-related toxicities. CONCLUSION Radiotherapy is effective in the treatment of patients with unresectable HCC. Its effect appeared to be more prominent within the site to which radiation was given. The combination of TACE and radiation was associated with better control of HCC than radiation given alone, probably due to the selection of patients with favorable prognosis for the combined treatment. A dose-volume model should be established in the next phase of research in the treatment of unresectable HCC.

Radiation-induced liver disease after three-dimensional conformal radiotherapy for patients with hepatocellular carcinoma: dosimetric analysis and implication.

PURPOSE To analyze the correlation of radiation-induced liver disease (RILD) with patient-related and treatment-related dose-volume factors and to describe the probability of RILD by a normal tissue complication probability (NTCP) model for patients with hepatocellular carcinoma (HCC) treated with three-dimensional conformal radiotherapy (3D-CRT). METHODS AND MATERIALS Between November 1993 and December 1999, 93 patients with intrahepatic malignancies were treated with 3D-CRT at our institution. Sixty-eight patients who were diagnosed with HCC and had complete 3D dose-volume data were included in this study. Of the 68 patients, 50 had chronic viral hepatitis before treatment, either type B or type C. According to the Child-Pugh classification for liver cirrhosis, 53 patients were in class A and 15 in class B. Fifty-two patients underwent transcatheter arterial chemoembolization with an interval of at least 1 month between transcatheter arterial chemoembolization and 3D-CRT to allow adequate recovery of hepatic function. The mean dose of radiation to the isocenter was 50.2 +/- 5.9 Gy, in daily fractions of 1.8-2Gy. No patient received whole liver irradiation. RILD was defined as Grade 3 or 4 hepatic toxicity according to the Common Toxicity Criteria of the National Cancer Institute. All patients were evaluated for RILD within 4 months of RT completion. Three-dimensional treatment planning with dose-volume histogram analysis of the normal liver was used to compare the dosimetric difference between patients with and without RILD. Maximal likelihood analysis was conducted to obtain the best estimates of parameters of the Lyman NTCP model. Confidence intervals of the fitted parameters were estimated by the profile likelihood method. RESULTS Twelve of the 68 patients developed RILD after 3D-CRT. None of the patient-related variables were significantly associated with RILD. No difference was found in tumor volume (780 cm(3) vs. 737 cm(3), p = 0.86), normal liver volume (1210 cm(3) vs. 1153 cm(3), p = 0.64), percentage of normal liver volume with radiation dose >30 Gy (V(30 Gy); 42% vs. 33%, p = 0.05), and percentage of normal liver volume with >50% of the isocenter dose (V(50%); 45% vs. 36%, p = 0.06) between patients with and without RILD. The mean hepatic dose was significantly higher in patients with RILD (2504 cGy vs. 1965 cGy, p = 0.02). The probability of RILD in patients could be expressed as follows: probability = 1/[1 + exp(-(0.12 x mean dose - 4.29))], with coefficients significantly different from 0. The best estimates of the parameters in the Lyman NTCP model were the volume effect parameter of 0.40, curve steepness parameter of 0.26, and 50% tolerance dose for uniform irradiation of whole liver [TD(50)(1)] of 43 Gy. Patients with RILD had a significantly higher NTCP than did those with no RILD (26.2% vs. 15.8%; p = 0.006), using the best-estimated parameters. CONCLUSION Dose-volume histogram analysis can be effectively used to quantify the tolerance of the liver to RT. Patients with RILD had received a significantly higher mean dose to the liver and a significantly higher NTCP. The fitted volume effect parameter of the Lyman NTCP model was close to that from the literature, but much lower in our patients with HCC and prevalent chronic viral hepatitis than that reported in other series with patients with normal liver function. Additional efforts should be made to test other models to describe the radiation tolerance of the liver for Asian patients with HCC and preexisting compromised hepatic reserve.

Long-term survival of nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy

PURPOSE The purpose of this study is to demonstrate long-term survival of nasopharyngeal carcinoma treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy. METHODS AND PATIENTS One hundred and seven patients with Stage III and IV (American Joint Committee on Cancer, AJCC, 1988) nasopharyngeal carcinoma (NPC) were treated with concomitant chemotherapy and radiotherapy (CCRT) followed by adjuvant chemotherapy between April 1990 and December 1997 in Koo Foundation Sun Yat-Sen Cancer Center, Taipei. The dose of radiation was 70 Gray (Gy) given in 35 fractions, 5 fractions per week. Two courses of chemotherapy, consisting of cisplatin and 5-fluorouracil, were delivered simultaneously with radiotherapy in Weeks 1 and 6 and two additional monthly courses were given after radiotherapy. According to the AJCC 1997 staging system, 32 patients had Stage II disease, 44 had Stage III, and 31 had Stage IV disease. RESULTS With median follow-up of 44 months, the 5-year overall survival rate in all 107 patients was 84.1%, disease-free survival rate was 74.4%, and locoregional control rate was 89.8%. The 3-year overall survival for Stage II was 100%, for Stage III it was 92.8%, and for Stage IV, 69. 4% (p = 0.0002). The 3-year disease-free survival for Stage II was 96.9%, for Stage III it was 87.7%, and for Stage IV it was 51.9% (p = 0.0001). CONCLUSION CCRT and adjuvant chemotherapy is effective in Taiwanese patients with advanced NPC. The prognosis of AJCC 1997 Stage II and III disease is excellent, but, for Stage IV (M0), it is relatively poor. Future strategies of therapy should focus on high-risk AJCC 1997 Stage IV (M0) cohort.

Unique features of breast cancer in Taiwan

Between April 1990 and December 1997, 811 consecutive patients with 830 newly diagnosed breast cancers having their primary treatments in our institution were included in this study. Sixty three percent of breast cancer patients were premenopausal. The early-onset breast cancer (age ≤ 40) composed 29.3% of all patients. The five-year survival rate of all patients was 80.4% (95% confidence interval [CI], 76.2–84.6%). The five-year overall survival rate for stage 0 was 95.7% (95% CI, 87.3–100%), stage I, 93.9% (95% CI, 88.9–98.9%), stage II, 88.5% (95% CI, 82.0–95.1%), stage III, 65.0% (95% CI, 54.0–75.9%), and stage IV, 18.5% (95% CI, 3.4–33.7%). Multivariate analysis of primary operable breast cancer revealed that axillary lymph node involvement, high nuclear grade and early-onset breast cancer (age ≤ 40) were poor prognostic factors. The early-onset breast cancer had a more aggressive clinical behavior than that of the older age group, their five-year disease-free survival rates for stage I, stage II and stage III diseases being only 64.7%, 66.5%, and 43.3%, respectively. In these patients the only meaningful prognostic factor was extensive axillary lymph node metastasis (≥10). In summary, breast cancer patients in Taiwan tend to be younger than their counterpart in western countries. The early-onset breast cancer had poorer prognostic features for all stages comparing to the older age group. Standard pathologic factors are not good predictors of their outcome. For these patients new biologic markers need to be sought to distinguish between high and low risk and the treatment strategy for them should be guided by the aggressive characteristics of the disease.

Radiation-induced liver disease after radiotherapy for hepatocellular carcinoma: clinical manifestation and dosimetric description

Twelve patients with hepatocellular carcinoma and chronic hepatitis developed radiation-induced liver disease (RILD) after three-dimensional conformal radiotherapy. Six patients died of RILD and six recovered. Mean prescribed dose was 50.6+/-4.3Gy, in a daily fraction of 1.8-2.0Gy. Commonly used dosimetric parameters, such as fraction volume of normal liver with radiation dose >30Gy, prediction score, and normal tissue complication probability, failed to differentiate the fatality and clinical types of this complication. Elevated transaminases are more frequently seen than ascites and elevated alkaline phosphamide are seen in patients with RILD.

Genomic Prediction of Locoregional Recurrence After Mastectomy in Breast Cancer

PURPOSE This study aims to explore gene expression profiles that are associated with locoregional (LR) recurrence in breast cancer after mastectomy. PATIENTS AND METHODS A total of 94 breast cancer patients who underwent mastectomy between 1990 and 2001 and had DNA microarray study on the primary tumor tissues were chosen for this study. Eligible patient should have no evidence of LR recurrence without postmastectomy radiotherapy (PMRT) after a minimum of 3-year follow-up (n = 67) and any LR recurrence (n = 27). They were randomly split into training and validation sets. Statistical classification tree analysis and proportional hazards models were developed to identify and validate gene expression profiles that relate to LR recurrence. RESULTS Our study demonstrates two sets of gene expression profiles (one with 258 genes and the other 34 genes) to be of predictive value with respect to LR recurrence. The overall accuracy of the prediction tree model in validation sets is estimated 75% to 78%. Of patients in validation data set, the 3-year LR control rate with predictive index more than 0.8 derived from 34-gene prediction models is 91%, and predictive index 0.8 or less is 40% (P = .008). Multivariate analysis of all patients reveals that estrogen receptor and genomic predictive index are independent prognostic factors that affect LR control. CONCLUSION Using gene expression profiles to develop prediction tree models effectively identifies breast cancer patients who are at higher risk for LR recurrence. This gene expression-based predictive index can be used to select patients for PMRT.

A pilot study of three‐dimensional conformal radiotherapy in unresectable hepatocellular carcinoma

Background : The purpose of this study was to determine the potential role of three‐dimensional (3‐D) conformal radiotherapy (RT) in treatment of unresectable hepatocellular carcinoma (HCC).

Examining prognostic factors and patterns of failure in nasopharyngeal carcinoma following concomitant radiotherapy and chemotherapy: impact on future clinical trials

PURPOSE Concomitant chemotherapy and radiotherapy (CCRT), followed by adjuvant chemotherapy, has improved the outcome of nasopharyngeal carcinoma (NPC). However, the prognosis and patterns of failure after this combined-modality treatment are not yet clear. In this report, the prognostic factors and failure patterns we observed with CCRT may shed new light in the design of future trials. METHODS AND PATIENTS One hundred forty-nine (149) patients with newly diagnosed and histologically proven NPC were prospectively treated with CCRT followed by adjuvant chemotherapy between April 1990 and December 1997. One hundred and thirty-three (89.3%) patients had MRI of head and neck for primary evaluation before treatment. Radiotherapy was delivered either at 2 Gy per fraction per day up to 70 Gy or 1.2 Gy per fraction, 2 fractions per day, up to 74.4 Gy. Chemotherapy consisted of cisplatin and 5-fluorouracil. According to the AJCC 1997 staging system, 32 patients were in Stage II, 53 in Stage III, and 64 in Stage IV (M0). RESULTS Univariate analysis revealed that WHO (World Health Organization) Type II histology, T4 classification, and parapharyngeal extension were poor prognostic factors for locoregional control. Multivariate analysis revealed that T4 disease was the most important adverse factor that affects locoregional control, the risk ratio being 5.965 (p = 0.02). Univariate analysis for distant metastasis revealed that T4 and N3 classifications, serum LDH level > 410 U/L (normal range, 180-460), parapharyngeal extension, and infiltration of the clivus were significantly associated with poor prognosis. Multivariate analysis, however, revealed that T4 classification and N3 category were the only two factors that predicted distant metastasis; the risk ratios were 3.994 (p = 0.02) and 3.390 (p = 0.01), respectively. Therefore, based on the risk factor analysis, we were able to identify low-, intermediate-, and high-risk patients. Low-risk patients were those without the risk factors mentioned above. They consisted of Stage II patients with T2aN0, T1N1, and T2aN1 categories and of Stage III patients with T1N2 and T2aN2 categories. Their risk of recurrence is low (4%). Intermediate-risk patients were those with at least one univariate risk factor. They are Stage II patients with T2bN0 and T2bN1 categories and Stage III patients with T2bN2 and T3N0-2 categories. The risk of recurrence is modest (18%). High-risk patients have risk factors by multivariate analysis. They are stage T4 or N3 patients. Their risk of recurrence is high (36%). CONCLUSION Low-risk patients have an excellent outcome. Future trials should focus on reducing treatment-associated toxicities and complications and reevaluate the benefit of sequential adjuvant chemotherapy. The recurrence in treatment of intermediate-risk patients is modest; CCRT and adjuvant chemotherapy may be the best standard for them. Patients with T4 and N3 disease have poorer prognosis. Hyperfractionated radiotherapy may be considered for the T4 patients. Future study in these high-risk patients should also address the problem of distant spread of the disease.

Concomitant Radiotherapy and Chemotherapy for Early-Stage Nasopharyngeal Carcinoma

PURPOSE Early-stage nasopharyngeal carcinoma (NPC) continues to carry a failure rate of 15% to 30% when treated with radiotherapy alone; the benefit of concomitant radiotherapy and chemotherapy (CCRT) in early-stage NPC is unclear. The purpose of this report is to describe our efforts to improve treatment outcome in early-stage NPC after CCRT. PATIENTS AND METHODS Of 189 newly diagnosed NPC patients without evidence of distant metastases who were treated in our institution between 1990 and 1997, 44 presented with early-stage (stage I and II) disease according to the American Joint Committee on Cancer (AJCC) 1997 NPC staging system. Twelve of these patients were treated with radiotherapy alone and 32 with CCRT. Each patients head and neck area was evaluated by magnetic resonance imaging or computed tomography. Radiotherapy was administered at 2 Gy per fraction per day, Monday through Friday, for 35 fractions for a total dose of 70 Gy. Chemotherapy consisting of cis-diamine-dichloroplatinum and fluorouracil was delivered simultaneously with radiotherapy in weeks 1 and 6 and sequentially for two monthly cycles after radiotherapy. RESULTS Patients who were treated with radiotherapy alone primarily had stage I disease, whereas none of those who were treated with CCRT had stage I disease (11 of 12 patients v none of 32 patients; P =.001). The locoregional control rate at 3 years for the radiotherapy group was 91.7% (median follow-up period, 34 months) and was 100% for the CCRT group (median follow-up period, 44 months) (P =.10). The 3-year disease-free survival rate in the radiotherapy group was 91.7% and was 96.9% in the CCRT group (P =.66). CONCLUSION Our results reveal excellent prognosis of AJCC 1997 stage II NPC treated with CCRT. Stage II patients with a greater tumor burden treated with CCRT showed an equal disease-free survival, compared with stage I patients treated with radiotherapy alone. A prospective randomized trial is underway to confirm the role of CCRT in stage II NPC.