Tumor/normal esophagus ratio in (18)F-fluorodeoxyglucose positron emission tomography/computed tomography for response and prognosis stratification after neoadjuvant chemotherapy for esophageal squamous cell carcinoma

Remarkable response as a new indicator for endoscopic evaluation of local efficacy of non-surgical treatments for esophageal cancer

In Japan, standard of care of the patients with resectable esophageal cancer is neoadjuvant chemotherapy (NAC) followed by esophagectomy. Patients unfitted for surgery or with unresectable locally advanced esophageal cancer are generally indicated with definitive chemoradiotherapy (CRT). Local disease control is undoubtful important for the management of patients with esophageal cancer, therefore endoscopic evaluation of local efficacy after non-surgical treatments must be essential. The significant shrink of primary site after NAC has been reported as a good indicator of pathological good response as well as favorable survival outcome after esophagectomy. And patients who could achieve remarkable shrink to T1 level after CRT had favorable outcomes with salvage surgery and could be good candidates for salvage endoscopic treatments. Based on these data, "Japanese Classification of Esophageal Cancer, 12th edition" defined the new endoscopic criteria "remarkable response (RR)", that means significant volume reduction after treatment, with the subjective endoscopic evaluation are proposed. In addition, the finding of local recurrence (LR) at primary site after achieving a CR was also proposed in the latest edition of Japanese Classification of Esophageal Cancer. The findings of LR are also important for detecting candidates for salvage endoscopic treatments at an early timing during surveillance after CRT. The endoscopic evaluation would encourage us to make concrete decisions for further treatment indications, therefore physicians treating patients with esophageal cancer should be well-acquainted with each finding.

Novel Advances in Qualitative Diagnostic Imaging for Decision Making in Multidisciplinary Treatment for Advanced Esophageal Cancer

Background: Recently, neoadjuvant therapy and the succeeding surgery for advanced esophageal cancer have been evaluated. In particular, the response to the therapy has been found to affect surgical outcomes, and thus a precise evaluation of treatment effect is important for this strategy. In this study, articles on qualitative diagnostic modalities to evaluate tumor activities were reviewed, and the diagnostic indices were examined. Methods: For prediction of the effect, perfusion CT and diffusion MRI were estimated. For the histological response evaluation, perfusion CT, diffusion-MRI, and FDG-PET were estimated. For downstaging evaluation of T4, tissue-selective image reconstruction using enhanced CT was estimated and diagnostic indices were reviewed. Results: The prediction of the effect using perfusion CT with 'pre CRT blood flow' and diffusion MRI with 'pre CRT ADC value'; the estimation of the histological response using perfusion CT with 'post CRT blood flow reduction, using diffusion MRI with 'post CRT ADC increasing', and using FDG-PET with 'post CRT SUV reduction'; and the downstaging evaluation of T4 using CT image reconstruction with 'fibrous changed layer' were performed well, respectively. Conclusions: Qualitative imaging modalities for prediction or response evaluation of neoadjuvant therapy for progressive esophageal cancer were useful for the decision making of the treatment strategy of the multidisciplinary treatment.

Maximum standardized uptake value change rate before and after neoadjuvant chemotherapy can predict early recurrence in patients with locally advanced esophageal cancer: a multi-institutional cohort study of 220 patients in Japan

BACKGROUND

Neoadjuvant chemotherapy (NAC) followed by esophagectomy can improve the prognosis of locally advanced esophageal cancer (LAEC). However, LAEC reportedly recurred in 17-21% of patients within 6 months post surgery. Thus, current treatment strategies may be inadequate for LAECs with poor prognosis. Preoperative identification of patients with poor prognosis might aid in modification of treatment strategies. This study aimed to evaluate the usefulness of the maximum standardized uptake value change rate (ΔSUV_max) in predicting treatment effects on the primary lesion, prognosis, and LAEC recurrence.

METHODS

This study involved 220 esophageal cancer patients who underwent esophagectomy after NAC at three facilities in Japan. The optimal cut-off point for ΔSUV_max in predicting tumor regression grade (TRG) was calculated and used to assess the correlation between ΔSUV_max and postoperative survival.

RESULTS

The optimal cut-off point for ΔSUV_max was 0.5. The 5-year overall survival rate in patients with ΔSUV_max ≥ 0.5 was significantly higher than that in patients with ΔSUV_max < 0.5 (71.5% vs. 50.5%, P = 0.001). Multivariate analysis identified ΔSUV_max (hazards ratio, 0.496; P = 0.004) as an independent prognostic factor. Among 199 patients evaluated for recurrence, 24 (12.1%) showed recurrence within 6 months post surgery. Univariate analysis revealed ΔSUV_max as the only predictor for early recurrence (odds ratio, 0.222; P = 0.004).

CONCLUSION

ΔSUV_max before and after NAC is clinically useful as it could help predict TRG, survival outcome, and early recurrence within 6 months post esophagectomy and is easily obtainable in general clinical practice. We believe that it may also help determine suitable treatment strategies for LAEC.

Evaluating the effect of Neoadjuvant chemotherapy for esophageal Cancer using the RECIST system with shorter-axis measurements: a retrospective multicenter study

Background

Evaluating the effect on primary lesions is important in determining treatment strategies for esophageal cancer. The Response Evaluation Criteria in Solid Tumors system, which employs the longest diameter for measuring tumors, is commonly used for evaluating treatment effects. However, the usefulness of these criteria in assessing primary esophageal tumors remains controversial. Thus, we evaluated this issue by measuring not only the longest diameter but also the shorter axis of the tumor.

Methods

We retrospectively reviewed data from 313 patients with esophageal cancer treated with neoadjuvant chemotherapy followed by esophagectomy at three major high-volume centers in Japan. All patients underwent contrast-enhanced computed tomography before and after chemotherapy. The longest and shortest tumor diameters were measured in each case. Treatment effects were adapted to the Response Evaluation Criteria in Solid Tumors system. Correlations between pathological and survival data were also analyzed.

Results

Inter-observer discrepancies were examined for changes in the longest diameter and shorter axis of the tumor (the intraclass correlation coefficients were 0.550 and 0.624, respectively). The shorter axis was correlated with the pathological response in the multivariate analysis (p < 0.001). The shorter axis was significantly associated with overall survival and disease-free survival (both p < 0.001), whereas this association was not observed for the longest tumor diameter.

Conclusions

This multicenter study demonstrated that the Response Evaluation Criteria in Solid Tumors system is useful for predicting pathological response and survival by incorporating the shorter axis of the primary esophageal tumor.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08747-y.

Novel Criterion Using Esophageal Major and Minor Axes is Useful to Evaluate the Therapeutic Effect and Prognosis After Neoadjuvant Chemotherapy Followed by Surgery in Locally Advanced Esophageal Cancer

BACKGROUND

An appropriate strategy is needed to determine the therapeutic effect of chemotherapy on primary lesions in esophageal cancer. This multicenter cohort study aimed to examine the usefulness of a novel criterion obtained by multiplying the lengths of the major and minor esophageal axes from helical computed tomography as a tool to evaluate the therapeutic effect of neoadjuvant chemotherapy and to predict prognosis after surgery in locally advanced esophageal cancer.

MATERIALS AND METHODS

A first investigation evaluated the reproducibility of the new criterion between two independent examiners. In a second investigation, we examined the association of the novel criterion with pathological tumor regression grade and long-term outcomes. Pretreatment primary lesions less than 20 mm on computed tomography were excluded.

RESULTS

In an initial cohort of 81 patients, the intraclass correlation coefficient for the novel criterion was higher than that for the tumor major axis both before and after neoadjuvant chemotherapy. In the second cohort of 255 patients, the novel criterion significantly correlated with tumor regression grade (p = 0.0003), overall survival (p < 0.0001), and disease-free survival (p < 0.0001). It was also an independent predictor for overall survival (p = 0.0023), along with age, tumor regression grade, and pathological stage.

CONCLUSIONS

The measurement derived by multiplying the esophageal major and minor axes on computed tomography is easy to obtain and has better objectivity and reproducibility for tumors of any shape. This novel criterion may be clinically useful because it can estimate therapeutic effect, tumor regression grade, and prognosis after neoadjuvant chemotherapy followed by surgery for esophageal cancer.

Positron emission tomography complete metabolic response as a favorable prognostic predictor in esophageal cancer following neoadjuvant chemotherapy with docetaxel/cisplatin/5-fluorouracil

BACKGROUND

¹⁸F-fluorodeoxyglucose-positron emission tomography (PET)/computed tomography is useful in diagnosing lymph node and distant metastases of esophageal cancer. However, its value for predicting survival is controversial.

AIM

To evaluate the value of PET complete metabolic response (CMR) as a prognostic predictor for esophageal cancer.

METHODS

Between June 2013 and December 2017, 58 patients with squamous cell esophageal cancer who underwent neoadjuvant chemotherapy (NAC) in Oita University were enrolled in this retrospective cohort study. Tumors were clinically staged using fluorodeoxyglucose-PET/computed tomography before and after NAC. After NAC, maximal standardized uptake value ≤ 2.5 was defined as PET-CMR, and maximal standardized uptake value > 2.5 was defined as non-PET-CMR. We compared short-term outcomes between the PET-CMR group and non-PET-CMR group and evaluated prognostic factors by univariate and multivariate analyses.

RESULTS

The PET-CMR group included 22 patients, and the non-PET-CMR group included 36 patients. There were no significant differences in intraoperative and postoperative complications between the two groups. Five-year relapse-free survival and overall survival in the PET-CMR group were significantly more favorable than those in the non-PET-CMR group (38.6 mo vs 20.8 mo, P = 0.021; 42.8 mo vs 25.1 mo, P = 0.011, respectively). PET-CMR was a significant prognostic factor in terms of relapse-free survival by univariate analysis (hazard ratio: 2.523; 95% confidence interval: 1.034–7.063; P < 0.041). Particularly, PET-computed tomography negative N was an independent prognostic factor of relapse-free survival and overall survival by multivariate analysis.

CONCLUSION

PET-CMR after NAC is considered a favorable prognostic factor for esophageal cancer. Evaluation by PET-computed tomography could be useful in clinical decision making for esophageal cancer.

Fusobacterium nucleatum confers chemoresistance by modulating autophagy in oesophageal squamous cell carcinoma

Background

Fusobacterium nucleatum (F. nucleatum) is a gut microbe implicated in gastrointestinal tumorigenesis. Predicting the chemotherapeutic response is critical to developing personalised therapeutic strategies for oesophageal cancer patients. The present study investigated the relationship between F. nucleatum and chemotherapeutic resistance in oesophageal squamous cell carcinoma (ESCC).

Methods

We examined the relationship between F. nucleatum and chemotherapy response in 120 ESCC resected specimens and 30 pre-treatment biopsy specimens. In vitro studies using ESCC cell lines and co-culture assays further uncovered the mechanism underlying chemotherapeutic resistance.

Results

ESCC patients with F. nucleatum infection displayed lesser chemotherapeutic response. The infiltration and subsistence of F. nucleatum in the ESCC cells were observed by transmission electron microscopy and laser scanning confocal microscopy. We also observed that F. nucleatum modulates the endogenous LC3 and ATG7 expression, as well as autophagosome formation to induce chemoresistance against 5-FU, CDDP, and Docetaxel. ATG7 knockdown resulted in reversal of F. nucleatum-induced chemoresistance. In addition, immunohistochemical studies confirmed the correlation between F. nucleatum infection and ATG7 expression in 284 ESCC specimens.

Conclusions

F. nucleatum confers chemoresistance to ESCC cells by modulating autophagy. These findings suggest that targeting F. nucleatum, during chemotherapy, could result in variable therapeutic outcomes for ESCC patients.

Total Lesion Glycolysis Ratio in Positron Emission Tomography/Computed Tomography Images During Neoadjuvant Chemotherapy Can Predict Pathological Tumor Regression Grade and Prognosis in Patients with Locally Advanced Squamous Cell Carcinoma of the Esophagus

BACKGROUND

The usefulness of quantitating tumor lesion glycolysis (TLG) from ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) findings as a tool for determining the effect of neoadjuvant chemotherapy (NAC) in esophageal squamous cell carcinoma (ESCC) has not yet been established.

METHODS

The cohort of this retrospective study comprised 46 patients who had undergone NAC and subsequent esophagectomy for locally advanced ESCC between January 2008 and December 2017. PET/CT was conducted before and after NAC to assess its therapeutic effect. Associations between changes in TLG values during NAC and clinicopathological findings, pathological tumor regression grade (TRG), and prognosis were assessed.

RESULTS

Most patients received two courses of DCF (Docetaxel, Cisplatin, and Fluorouracil) as NAC. The mean TLG value of the primary tumor decreased significantly after NAC. The median follow-up period was 41 months. The Kaplan-Meier method, analyzed by log-rank test, showed that low TLG ratio (≤ 0.4) and low SUV_max ratio (≤ 0.6) were associated with favorable survival outcomes (P = 0.0073 and P = 0.032, respectively). Univariate and multivariate analysis revealed that TLG ratio and achievement of pathological cure were independent prognostic factors for overall survival. TLG ratio was also associated with pathological TRG (TRG 0-1a vs 1b-3) (P = 0.0016).

CONCLUSIONS

TLG ratio before and after NAC is clinically useful in predicting both histological response and survival outcome after NAC and subsequent esophagectomy in patients with ESCC.

The Prognostic Significance of Metastatic Nodal Size in Non-surgical Patients With Esophageal Squamous Cell Carcinoma

Background: The present study aimed to determine the prognostic value of the size of metastatic lymph node (LN) in non-surgical patients with esophageal squamous cell carcinoma (ESCC).

Methods: Three hundred seventy-six ESCC patients treated with definitive (chemo-) radiotherapy from January 2013 to March 2016 were reviewed. We analyzed potential associations of metastatic nodal size with responses, patterns of failure, and survival. Log-rank testing and Cox proportional hazards regression models were used to assess the impact of the clinical factors on survival.

Results: The 3-years over survival (OS) rates following a median follow-up of 28.2 months were 53.2, 46.2, 35.5, and 22.7% for the N0 group, the >0.5 to ≤1 cm group, the >1 to ≤2 cm group, and the >2 cm group, respectively. The progression-free survival (PFS) rates for 2 years were 50.9, 44.2, 26.6, and 23.4% for the N0 group, the >0.5 to ≤1 cm group, the >1 to ≤2 cm group, and the >2 cm group, respectively. The objective response rates (ORR) for the 280 patients with metastatic LNs were 43.1% for the LN >0.5 to ≤1 cm group, 46.9% for the LN >1 to ≤2 cm group, and 25.5% for the LN ≥2 cm group. The LN >2 cm group had the worst ORR of the three groups with LNs. Gross tumor volume (GTV) failure was the most common failure pattern, followed by distant failure and out of GTV LN failure, with incidences of 47.9% (180 of 376), 42% (158 of 376), and 13.8% (52 of 376), respectively. Nodal size correlated statistically with GTV failure and distant failure but not with out-of-GTV nodal failure. After adjusting for age, sex, T category, Primary tumor location, and CRT, the size of metastatic LNs was an independent prognostic factor for OS and PFS in multivariate analyses.

Conclusions: Nodal size is one of prognostic factors for non-surgical patients with ESCC and correlated statistically with GTV failure and distant failure.

Clinical significance of evaluating endoscopic response to neoadjuvant chemotherapy in esophageal squamous cell carcinoma

BACKGROUND AND AIM

Clinical significance of endoscopic response (ER) after neoadjuvant chemotherapy (NAC) for esophageal cancer has not been fully understood. Thus, the present study aimed to investigate the association between ER to NAC and its clinicopathological outcomes in patients with esophageal squamous cell carcinoma (ESCC).

METHODS

In total, 141 patients who underwent NAC and subsequent esophagectomy for ESCC were included. ER to NAC was retrospectively evaluated based on macroscopic findings of the primary tumor, which was classified into three categories: endoscopic no response (eNR), endoscopic partial response (ePR), and endoscopic good response (eGR). An endoscopic responder was defined as patients with eGR/ePR.

RESULTS

Approximately 89.4% of patients had cStage II-III disease, and 7.1% had pathological complete response. Upon ER evaluation, eNR, ePR, and eGR were observed in 46 (32.6%), 54 (38.3%), and 41 (29.1%) patients, respectively. Pathological responders significantly increased as the ER grade became better. Among preoperative clinical factors, only ER significantly correlated with pathological response in univariate and multivariate analysis. Endoscopic responders showed a significantly better prognosis than did eNR patients (P < 0.001), although the overall survival (OS) of the patients with eGR and ePR was equivalent. Endoscopic responder, ypT, ypN, and pathological responder were significant predictors of OS in the univariate analysis, and endoscopic responder, ypN, and pathological responder were independent predictors in the multivariate analysis.

CONCLUSION

This study suggests that ER can be a simple and important tool to predict the pathological response and survival of patients who undergo NAC for ESCC.

Association of the primary tumor's SUVmax with survival after surgery for clinical stage IA esophageal cancer: a single-center retrospective study

BACKGROUND

Compared to other esophageal cancers, clinical stage IA esophageal cancer generally has a good prognosis, although a subgroup of patients has a poor prognosis. Unfortunately, clinical diagnoses of invasion depth or lymph node metastasis are not always accurate, which make it difficult to identify patients with a high risk of postoperative recurrence using the tumor-node-metastasis staging system. Fluorodeoxyglucose-positron emission tomography may help guide the identification of malignant tumors and the evaluation of their malignant grade based on glucose metabolism. We aimed to evaluate the association between pre-operative fluorodeoxyglucose-positron emission tomography findings and the postoperative prognosis of patients with clinical stage IA esophageal cancer.

METHODS

This single-center retrospective study evaluated pre-esophagectomy fluorodeoxyglucose-positron emission tomography findings from 38 patients with clinical stage IA esophageal cancer. Receiver operating characteristic curve analysis was performed to evaluate the prognostic significance of the primary tumor having low and high SUVmax values (cut-off: 3.56).

RESULTS

Overall survival (log-rank p = 0.034) and progression-free survival (log-rank p = 0.008) were significantly different between the groups with low SUVmax values (n = 18) and high SUVmax values (n = 20). Furthermore, the primary tumor's SUVmax value was related to pathological vascular invasion (p = 0.045) and distant metastasis (p = 0.042).

CONCLUSION

The SUVmax of the primary tumor is a predictor of postoperative survival for clinical stage IA esophageal cancer. Thus, using fluorodeoxyglucose-positron emission tomography to evaluate the primary tumor's glucose metabolism may reflect the tumor's grade and potentially compensate for inaccuracies in tumor-node-metastasis staging.

Intratumoral Fusobacterium Nucleatum Levels Predict Therapeutic Response to Neoadjuvant Chemotherapy in Esophageal Squamous Cell Carcinoma

PURPOSE

Emerging evidence indicates that gut microbiome plays a crucial role in the cancer pathogenesis. Although Fusobacterium nucleatum (F. nucleatum) is associated with poor prognosis in multiple cancers, its clinical significance in predicting response to chemotherapy in patients with esophageal squamous cell carcinoma (ESCC) remains unclear.

EXPERIMENTAL DESIGN

The F. nucleatum levels were quantified by qPCR assays in tumor tissues from 551 patients with ESCC from two independent cohorts, including 101 patients who received neoadjuvant chemotherapy prior to curative resection. Associations between F. nucleatum burden and recurrence-free survival (RFS), as well with chemotherapeutic response were evaluated using response evaluation criteria in solid tumors (RECISTs), primary tumor metabolic response defined by maximum standardized uptake value (SUVmax) changes in positron emission tomography-CT (PET/CT), and pathologic tumor regression grade (TRG).

RESULTS

High burden of F. nucleatum in patients with ESCC associated with poor RFS in both training [log-rank P = 0.02; HR = 1.61; P = 0.03] and validation cohorts (log-rank P = 0.003; HR = 1.96; P = 0.004). Importantly, patients with ESCC with high levels of F. nucleatum displayed poor chemotherapeutic response for all three evaluation methods: RECIST (P = 0.04), SUVmax change in PET/CT (P = 0.0004), and TRG (P = 0.003).

CONCLUSIONS

We conclude that high levels of intratumoral F. nucleatum have a prognostic significance for predicting poor RFS in patients with ESCC. More importantly, our data indicates that higher F. nucleatum burden correlates with poor response to neoadjuvant chemotherapy, suggesting the possibility that an antibiotic intervention against this bacterium may significantly improve therapeutic response in patients with ESCC.

18F-fluorodeoxyglucose positron emission tomography predicts lymph node responses to definitive chemoradiotherapy in esophageal squamous cell carcinoma patients

Purpose

To evaluate the capability of ¹⁸F-fluorodeoxyglucose positron emission tomography/ computed tomography (¹⁸F-FDG-PET/CT) to predict the clinical response of metastatic lymph node (mLN) to definitive chemoradiotherapy (dCRT) and guide personalized radiation dose in esophageal squamous cell carcinoma (ESCC) patients.

Patients and methods

One hundred and forty-three mLNs from 59 patients with ESCC treated with dCRT and who had undergone a pretreatment ¹⁸F-FDG-PET/CT scan were included in the study. All defined mLNs were contoured by nuclear medicine radiologists. Response was evaluated by contrast-enhanced computed tomography and ¹⁸F-FDG-PET/CT.

Results

Sixty-nine mLNs showed complete response (CR), and 74 mLNs showed non-complete response. The 143 mLNs were divided into 4 groups (Groups 1–4) based on the quartiles of maximum standardized uptake value (SUVmax-G1, SUVmax-G2, SUVmax-G3, and SUVmax-G4) and metabolic tumor volume (MTV-G1, MTV-G2, MTV-G3, and MTV-G4). The CR rate of SUVmax-G2 was significantly higher than the other 3 groups. The escalated radiation dose improved the CR rate of lymph nodes in SUVmax-G3 (55 Gy) and SUVmax-G4 (61 Gy). The lowest CR rate was found in MTV-G4 (the group with the largest MTV). The escalated radiation dose (59.7 Gy) improved the CR rate of lymph node in MTV-Groups 3 and 4.

Conclusion

Pretreatment metabolic parameters can predict the response of mLNs to dCRT for patients with ESCC. The parameters could also be used to guide personalized dose to mLNs.

A Novel Theranostic Combination of Near-infrared Fluorescence Imaging and Laser Irradiation Targeting c-KIT for Gastrointestinal Stromal Tumors

It is difficult to distinguish gastrointestinal stromal tumors (GISTs) from other types of submucosal tumors under conventional gastrointestinal endoscopy. We aimed to detect GISTs by molecular fluorescence imaging using a near-infrared (NIR) photosensitizer (IR700)-conjugated anti-c-KIT antibody and to treat GISTs by photoimmunotherapy with NIR irradiation as a non-invasive theranostic procedure. We also investigated the therapeutic mechanisms. Methods: Human GIST cell lines GIST-T1 and GIST-882M were incubated with IR700-conjugated anti-c-KIT antibody, IR700-12A8, and observed by confocal laser microscopy. Mice with GIST-T1 xenografts or rats with orthotopic xenografts were injected with IR700-12A8 or AF488-conjugated antibody, and observed under IVIS or autofluorescence imaging (AFI) endoscopy. GIST cells were treated with IR700-12A8 and NIR light in vitro and vivo, and cell viability, histology and apoptosis were evaluated. Results: Strong red fluorescence of IR700-12A8 was observed on the cell membrane of GIST cells and was gradually internalized into the cytoplasm. Tumor-specific accumulation of IR700-12A8 was observed in GIST-T1 xenografts in mice. Under AFI endoscopy, a strong fluorescence signal was observed in orthotopic GIST xenografts in rats through the normal mucosa covering the tumor. The percentage of dead cells significantly increased in a light-dose-dependent manner and both acute necrotic and late apoptotic cell death was observed with annexin/PI staining. Cleaved PARP expression was significantly increased after IR700-12A8-mediated NIR irradiation, which was almost completely reversed by NaN₃. All xenograft tumors (7/7) immediately regressed and 4/7 tumors completely disappeared after IR700-12A8-mediated NIR irradiation. Histologic assessment and TUNEL staining revealed apoptosis in the tumors. Conclusion: NIR fluorescence imaging using IR700-12A8 and subsequent NIR irradiation could be a very effective theranostic technology for GIST, the underlying mechanism of which appears to involve acute necrosis and supposedly late apoptosis induced by singlet oxygen.

Esophageal cancer: The latest on chemoprevention and state of the art therapies

Esophageal cancer is currently the 8th most common cancer worldwide and the 6th leading cause of cancer-related mortality. Despite remarkable advances, the mortality for those suffering from esophageal cancer remains high, with 5-year survival rates of less than 20%. In part, because most patients present with late-stage disease, long-term survival even after resection and therapy is disappointingly low. As we will discuss in this review, multiple characteristics specific to the disease stage and patient must be considered when choosing a treatment plan. This article will summarize current standard therapies, potential application of chemoprevention drugs and the promise and partial failure of personalized medicine, as well as novel treatments addressing this disease.

PET-Based Personalized Management in Clinical Oncology: An Unavoidable Path for the Foreseeable Future

It is imperative that the thrust of clinical practice in the ensuing years would be to develop personalized management model for various disorders. PET-computed tomography (PET-CT) based molecular functional imaging has been increasingly utilized for assessment of tumor and other nonmalignant disorders and has the ability to explore disease phenotype on an individual basis and address critical clinical decision making questions related to practice of personalized medicine. Hence, it is essential to make a concerted systematic effort to explore and define the appropriate place of PET-CT in personalized clinical practice in each of malignancies, which would strengthen the concept further. The potential advantages of PET based disease management can be classified into broad categories: (1) Traditional: which includes assessment of disease extent such as initial disease staging and restaging, treatment response evaluation particularly early in the course and thus PET-CT response adaptive decision for continuing the same regimen or switching to salvage schedules; there has been continuous addition of newer application of PET based disease restaging in oncological parlance (eg, Richter transformation); (2) Recent and emerging developments: this includes exploring tumor biology with FDG and non-FDG PET tracers. The potential of multitracer PET imaging (particularly new and novel tracers, eg, 68Ga-DOTA-TOC/NOC/TATE in NET, 68Ga-PSMA and 18F-fluorocholine in prostate carcinoma, 18F-fluoroestradiol in breast carcinoma) has provided a scientific basis to stratify and select appropriate targeted therapies (both radionuclide and nonradionuclide treatment), a major boost for individualized disease management in clinical oncology. Integrating the molecular level information obtained from PET with structural imaging further individualizing treatment plan in radiation oncology, precision of interventions and biopsies of a particular lesion and forecasting disease prognosis.