Fei-Fei Liu

Radiotherapy with or without hyperthermia in the treatment of superficial localized breast cancer: Results from five randomized controlled trials

PURPOSE Claims for the value of hyperthermia as an adjunct to radiotherapy in the treatment of cancer have mostly been based on small Phase I or II trials. To test the benefit of this form of treatment, randomized Phase III trials were needed. METHODS AND MATERIALS Five randomized trials addressing this question were started between 1988 and 1991. In these trials, patients were eligible if they had advanced primary or recurrent breast cancer, and local radiotherapy was indicated in preference to surgery. In addition, heating of the lesions and treatment with a prescribed (re)irradiation schedule had to be feasible and informed consent was obtained. The primary endpoint of all trials was local complete response. Slow recruitment led to a decision to collaborate and combine the trial results in one analysis, and report them simultaneously in one publication. Interim analyses were carried out and the trials were closed to recruitment when a previously agreed statistically significant difference in complete response rate was observed in the two larger trials. RESULTS We report on pretreatment characteristics, the treatments received, the local response observed, duration of response, time to local failure, distant progression and survival, and treatment toxicity of the 306 patients randomized. The overall CR rate for RT alone was 41% and for the combined treatment arm was 59%, giving, after stratification by trial, an odds ratio of 2.3. Not all trials demonstrated an advantage for the combined treatment, although the 95% confidence intervals of the different trials all contain the pooled odds ratio. The greatest effect was observed in patients with recurrent lesions in previously irradiated areas, where further irradiation was limited to low doses. CONCLUSION The combined result of the five trials has demonstrated the efficacy of hyperthermia as an adjunct to radiotherapy for treatment of recurrent breast cancer. The implication of these encouraging results is that hyperthermia appears to have an important role in the clinical management of this disease, and there should be no doubt that further studies of the use of hyperthermia are warranted.

The stress-activated protein kinase pathway mediates cell death following injury induced by cis-platinum, UV irradiation or heat

BACKGROUND Stimuli that stress cells, including inflammatory cytokines, ultra-violet irradiation, DNA-damaging chemotherapeutic drugs and heat shock, stimulate a recently identified cytoplasmic signaling system that is structurally related to the mitogen-activated protein kinase pathway. This pathway consists of a cascade of protein kinases including stress-activated protein kinase (SAPK), also termed Jun N-terminal kinase (JNK), and two kinases that activate it, MEKK and SEK/MKK4. Despite rapid progress in delineating the components of this pathway, the cellular consequence of its activation remains to be defined. RESULTS We have screened cells for defects in SAPK signaling and identified a cell line, previously characterized for its thermotolerance properties, as being more refractive to SAPK activation induced by heat stress than its thermosensitive parental line. Stable expression of dominant inhibiting SEK mutants in thermosensitive parental cells specifically and effectively blocked SAPK activation after heat shock. These lines also became markedly resistant to the cytocidal effects of thermal stress, confirming the phenotype of the thermotolerant line. These cell lines defective in SAPK activation were also resistant to the lethal effects of the DNA-damaging drug cis-platinum. CONCLUSIONS Experimentally induced stable blockade of SAPK activation in cells with normal thermosensitivity is sufficient to confer resistance to cell death induced by diverse stimuli including heat and the chemotherapeutic agent cis-platinum. These results suggest that activation of the SAPK pathway by diverse cell stressors plays a critical part in mediating the toxicity of these treatments and inducing cell death. SAPK activation in this context could broadly influence cellular response to stress, modulate apoptosis during development or determine the clinical response of tumor cells to cytotoxic therapies.

Caspase 3–mediated stimulation of tumor cell repopulation during cancer radiotherapy

In cancer treatment, apoptosis is a well-recognized cell death mechanism through which cytotoxic agents kill tumor cells. Here we report that dying tumor cells use the apoptotic process to generate potent growth-stimulating signals to stimulate the repopulation of tumors undergoing radiotherapy. Furthermore, activated caspase 3, a key executioner in apoptosis, is involved in the growth stimulation. One downstream effector that caspase 3 regulates is prostaglandin E2 (PGE2), which can potently stimulate growth of surviving tumor cells. Deficiency of caspase 3 either in tumor cells or in tumor stroma caused substantial tumor sensitivity to radiotherapy in xenograft or mouse tumors. In human subjects with cancer, higher amounts of activated caspase 3 in tumor tissues are correlated with markedly increased rate of recurrence and death. We propose the existence of a cell death–induced tumor repopulation pathway in which caspase 3 has a major role.

Deintensification Candidate Subgroups in Human Papillomavirus-Related Oropharyngeal Cancer According to Minimal Risk of Distant Metastasis

PURPOSE To define human papillomavirus (HPV) -positive oropharyngeal cancers (OPC) suitable for treatment deintensification according to low risk of distant metastasis (DM). PATIENTS AND METHODS OPC treated with radiotherapy (RT) or chemoradiotherapy (CRT) from 2001 to 2009 were included. Outcomes were compared for HPV-positive versus HPV-negative patients. Univariate and multivariate analyses identified outcome predictors. Recursive partitioning analysis (RPA) stratified the DM risk. RESULTS HPV status was ascertained in 505 (56%) of 899 consecutive OPCs. Median follow-up was 3.9 years. HPV-positive patients (n = 382), compared with HPV-negative patients (n = 123), had higher local (94% v 80%, respectively, at 3 years; P < .01) and regional control (95% v 82%, respectively; P < .01) but similar distant control (DC; 90% v 86%, respectively; P = .53). Multivariate analysis identified that HPV negativity (hazard ratio [HR], 2.9; 95% CI, 2.0 to 5.0), N2b-N3 (HR, 2.9; 95% CI, 1.8 to 4.9), T4 (HR, 1.8; 95% CI, 1.2 to 2.9), and RT alone (HR, 1.8; 95% CI, 1.1 to 2.5) predicted a lower recurrence-free survival (RFS; all P < .01). Smoking pack-years > 10 reduced overall survival (HR, 1.72; 95% CI, 1.1 to 2.7; P = .03) but did not impact RFS (HR, 1.1; 95% CI, 0.7 to 1.9; P = .65). RPA segregated HPV-positive patients into low (T1-3N0-2c; DC, 93%) and high DM risk (N3 or T4; DC, 76%) groups and HPV-negative patients into different low (T1-2N0-2c; DC, 93%) and high DM risk (T3-4N3; DC, 72%) groups. The DC rates for HPV-positive, low-risk N0-2a or less than 10 pack-year N2b patients were similar for RT alone and CRT, but the rate was lower in the N2c subset managed by RT alone (73% v 92% for CRT; P = .02). CONCLUSION HPV-positive T1-3N0-2c patients have a low DM risk, but N2c patients from this group have a reduced DC when treated with RT alone and seem less suited for deintensification strategies that omit chemotherapy.

Comparative Prognostic Value of HPV16 E6 mRNA Compared With In Situ Hybridization for Human Oropharyngeal Squamous Carcinoma

PURPOSE A significant proportion of oropharyngeal squamous cell carcinomas (OSCC) are associated with the human papilloma virus (HPV), particularly HPV16. The optimal method for HPV determination on archival materials however, remains unclear. We compared a quantitative real-time polymerase chain reaction (qRT-PCR) assay for HPV16 mRNA to a DNA in situ hybridization (ISH) method, and evaluated their significance for overall (OS) and disease-free (DFS) survival. PATIENTS AND METHODS Matched, archival biopsies from 111 patients with OSCC were evaluated for HPV16 using a qRT-PCR for E6 mRNA and ISH for DNA. Immunohistochemistry for p16, p53, and epidermal growth factor receptor were also performed. RESULTS HPV16 E6 mRNA was positive in 73 (66%) of 111 samples; ISH was positive in 62 of 106 samples (58%), with 86% concordance. P16 was overexpressed in 72 samples (65%), which was strongly associated with HPV16 status by either method. E6 mRNA presence or p16 overexpression were significantly associated with superior OS; E6 mRNA, HPV16 ISH, or p16 were all significantly associated with DFS. On multivariate analysis adjusted for age, stage, and treatment, positive E6 mRNA was the only independent predictor for superior OS; for DFS, p16 expression or HPV16 status determined by either method was significant. CONCLUSION The prevalence of HPV16 in OSCC ranges from 58% to 66%, in a recently treated Canadian cohort. Classification of HPV-positivity by HPV16 E6 mRNA, HPV16 ISH or p16 immunohistochemistry (IHC) is associated with improved DFS. However, the latter two assays are technically easier to perform; hence, HPV16 ISH or p16 IHC should become standard evaluations for all patients with OSCC.

Robust global micro-RNA profiling with formalin-fixed paraffin-embedded breast cancer tissues

Global micro-RNA (miR) profiling of human malignancies is increasingly performed, but to date, the majority of such analyses have used frozen tissues. However, formalin fixation is the standard and routine histological practice for optimal preservation of cellular morphology. To determine whether miR analysis of formalin-fixed tissues is feasible, quantitative real-time PCR (qRT-PCR) profiling of miR expression in 40 archival formalin-fixed paraffin-embedded (FFPE) breast lumpectomy specimens were performed. Taqman Low Density Arrays (TLDAs) were used to assess the expression level of 365 miRs in 34 invasive ductal carcinomas and in 6 normal comparators derived from reduction mammoplasties. Its technical reproducibility was high, with intra-sample correlations above 0.9 and with 92.8% accuracy in differential expression comparisons, indicating such global profiling studies to be technically and biologically robust. The TLDA data were confirmed using conventional single-well qRT-PCR analysis, showing a strong and statistically significant concordance between these two methods. Paired frozen and FFPE breast cancer samples from the same patients showed a similar level of robust correlation of at least 0.94. Compared with normal breast samples, a panel of miRs was consistently dysregulated in breast cancer, including earlier-reported breast cancer-related miRs, such as upregulated miR-21, miR-155, miR-191, and miR-196a, and downregulated miR-125b and miR-221. Additional novel miR sequences of potential biological relevance were also uncovered. These results show the validity and utility of conducting global miR profiling using FFPE samples, thereby offering enormous opportunities to evaluate archival banks of such materials, linked to clinical databases, to rapidly acquire greater insight into the clinically relevant role for miRs in human malignancies.

The surgical margin in soft-tissue sarcoma

In a retrospective review of 231 patients who were referred to Princess Margaret Hospital because of a soft-tissue sarcoma in an extremity, 100 patients were identified who had no metastases when they were first seen and who had been treated by local resection and adjuvant radiation therapy. Complete data were collected for each patient for the following variables: age; sex; location of the tumor and its size, grade, depth, and compartmental status; chemotherapy; and dose of radiation. The surgical margins were characterized as positive or negative for histological evidence of disease on the basis of an independent review of the pathological and operative reports by a surgeon and a radiation oncologist who were experienced in the management of sarcoma. Cox multivariate analysis was used to determine which of these variables contributed to local recurrence and evidence of systemic disease. Adequacy of the margin of resection was the only variable that was associated with local relapse (p = 0.0004). The size of the tumor (p = 0.0008) was the major determinant of the risk of systemic disease.

Refining American Joint Committee on Cancer/Union for International Cancer Control TNM Stage and Prognostic Groups for Human Papillomavirus–Related Oropharyngeal Carcinomas

PURPOSE To refine stage and prognostic group for human papillomavirus (HPV) -related nonmetastatic (M0) oropharyngeal cancer (OPC). METHODS All patients with nonmetastatic (M0) p16-confirmed OPC treated with radiotherapy with or without chemotherapy from 2000 to 2010 were included. Overall survival (OS) was compared among TNM stages for patients with HPV-related and HPV-unrelated OPC separately. For HPV-related OPC, recursive partitioning analysis (RPA) derived new RPA stages objectively. Cox regression was used to calculate adjusted hazard ratios (AHRs) to derive AHR stages. The performance of survival prediction of RPA stage and AHR stage was assessed against the current seventh edition TNM stages. Prognostic groups were derived by RPA, combining RPA stage and nonanatomic factors. RESULTS The cohort comprised 573 patients with HPV-related OPC and 237 patients with HPV-unrelated OPC, with a median follow-up of 5.1 years. Lower 5-year OS with higher TNM stage was evident for patients with HPV-unrelated OPC (stage I, II, III, and IV 5-year OS: 70%, 58%, 50%, and 30%, respectively; P = .004) but not for patients with HPV-related OPC (stage I, II, III, and IV 5-year OS: 88%, 78%, 71%, and 74%, respectively; P = .56). RPA divided HPV-related OPC into RPA-I (T1-3N0-2b), RPA-II (T1-3N2c), and RPA-III (T4 or N3; 5-year OS: 82%, 76%, and 54%, respectively; P < .001). AHR also yielded a valid classification, but RPA stage demonstrated better survival prediction. A further RPA (including RPA stage, age, and smoking pack-years [PYs]) derived the following four valid prognostic groups for survival: group I (T1-3N0-N2c_≤ 20 PY), group II (T1-3N0-N2c_> 20 PY), group III (T4 or N3_age ≤ 70), and group IVA (T4 or N3_age > 70; 5-year OS: 89%, 64%, 57%, and 40%, respectively; P < .001). CONCLUSION An RPA-based TNM stage grouping (stage I/II/III: T1-3N0-N2b/T1-3N2c/T4 or N3, with M1 as stage IV) is proposed for HPV-related OPC as a result of significantly improved survival prediction compared with the seventh edition TNM, and prognostication is further improved by an RPA-based prognostic grouping within the American Joint Committee on Cancer/Union for International Cancer Control TNM framework for HPV-related OPC.

T1/T2 GLOTTIC CANCER MANAGED BY EXTERNAL BEAM RADIOTHERAPY: THE INFLUENCE OF PRETREATMENT HEMOGLOBIN ON LOCAL CONTROL

Abstract Purpose: Pretreatment hemoglobin (Hb) level has been reported to be an important prognostic factor for local control and survival in various malignancies. However, in many settings, the adverse effect of a low Hb may be related to more advanced disease. The purpose of this analysis was to assess the influence of pretreatment Hb on local control in a large series of patients with a localized cancer (T1/T2 glottic cancer, AJCC 1992) treated in a standard fashion. Materials and Methods: Between January 1981 and December 1989, 735 patients (median age 63; 657 males, 78 females) with T1/T2 glottic cancer were treated with radiation therapy (RT). The standard RT prescription was 50 Gy in 20 fractions over 4 weeks (97% of patients). Factors studied for prognostic importance for local failure included pretreatment Hb, age, sex, T category, anterior commissure involvement, subglottic extension, and tumor bulk (presence of visible tumor vs. subclinical disease). Results: With a median follow-up of 6.8 years (range 0.2–14.3), 131 patients have locally relapsed for an actuarial 5-year relapse-free rate of 81.7%. The 5-year actuarial survival was 75.8%. The mean pretreatment hemoglobin level was 14.8 g/dl and was similar in all prognostic categories. On multivariate analysis, using the Cox proportional hazards model, pretreatment Hb predicted for local failure after RT. The hazard ratio (HR) for relapse was calculated for various Hb levels. For example, the HR for a Hb of 12 g/dl vs. a Hb of 15 g/dl was 1.8 (95% confidence interval 1.2–2.5). Previously established factors, including gender, T category, subglottic extension, as well as tumor bulk, were also prognostically important for local control. Conclusions: This analysis, in a large number of similarly treated patients, indicates that pretreatment Hb is an independent prognostic factor for local control in patients with T1/T2 carcinoma of the glottis treated with RT. The underlying biology of this observation needs to be explored, and using this information, it may be possible to develop strategies to improve treatment outcome.

MicroRNA-301 Mediates Proliferation and Invasion in Human Breast Cancer

Several microRNAs have been implicated in human breast cancer but none to date have been validated or utilized consistently in clinical management. MicroRNA-301 (miR-301) overexpression has been implicated as a negative prognostic indicator in lymph node negative (LNN) invasive ductal breast cancer, but its potential functional impact has not been determined. Here we report that in breast cancer cells, miR-301 attenuation decreased cell proliferation, clonogenicity, migration, invasion, tamoxifen resistance, tumor growth, and microvessel density, establishing an important oncogenic role for this gene. Algorithm-based and experimental strategies identified FOXF2, BBC3, PTEN, and COL2A1 as candidate miR-301 targets, all of which were verified as direct targets through luciferase reporter assays. We noted that miR-301 is located in an intron of the SKA2 gene which is responsible for kinetochore assembly, and both genes were found to be coexpressed in primary breast cancer samples. In summary, our findings define miR-301 as a crucial oncogene in human breast cancer that acts through multiple pathways and mechanisms to promote nodal or distant relapses.