ONCOLOGY Vol 19 No 2

Dr Gundry comprehensivelydiscusses the role of breastmagnetic resonance imaging(MRI) in staging and screening breastcancer. I will emphasize and expandon some of the author’s key points.

Although patients with lung cancer have benefited from advancesin diagnostic techniques, surgery, chemotherapy, and radiation, infectionfrequently complicates the course of cancer treatment. Infectionmay be caused by the tumor itself, by antineoplastic therapy, or by supportivecare measures. Recognition of risk factors for infection is critical.The relationship between an underlying immune defect and certaininfections is well documented. Diagnosis may be complicated bythe paucity of signs and symptoms or by an atypical presentation. Promptinstitution of empiric antimicrobial therapy is usually warranted, particularlyin life-threatening infections. This review will focus on theepidemiology, diagnosis, and management of particular infections thatcan occur in patients with lung cancer.

Lung cancer is the most commoncause of cancer-relatedmortality in the United Statesand worldwide.[1] In the UnitedStates, lung cancer was responsiblefor an estimated 160,440 deaths in2004. This surpassed the combinedmortality resulting from colorectal,breast, and prostate cancer.

In their article, Rusthoven and colleagueshighlight the utility ofcombined positron-emission tomography/computed tomography(PET-CT) imaging for diagnosing primaryand recurrent head and neckcarcinoma, and for defining tumor targetvolumes for radiotherapy treatmentplanning in the head and neck. PEToffers noninvasive measures of tumorbiology yet suffers from limited spatialresolution; the physiologic informationobtained with PET is complementaryto the high-resolution structural informationobtained with CT or magneticresonance imaging (MRI).

The most common indolent lymphoma, follicular lymphoma comprises 35% of adult non-Hodgkin’s lymphoma (NHL) in the United States and 22% worldwide. Features associated with adverse outcome include age, male gender, disease stage, and performance status, with the International Prognostic Index being the most widely used risk classification system. Long-term disease-free survival is possible in select patient subgroups after treatment, but very late relapses suggest that quiescent lymphoma cells might be harbored for long periods of time. Radiation therapy is the mainstay of treatment for limited-stage follicular lymphoma, but there is some experience with chemotherapy and combined chemoradiation. When to initiate treatment in patients with advanced disease is controversial, but options include various combined chemotherapy regimens, monoclonal antibodies, radiolabeled antibodies, and bone marrow or stem cell transplantation. Future directions in the treatment of follicular lymphoma include vaccines, antisense therapy, and proteasome inhibitors.

Dr. Ganti and colleagues from the University of Nebraska provide a thorough review of the management of patients with follicular lymphoma, including many recent additions to the therapeutic armamentarium. The field is rapidly changing, and this article will be an enduring resource both for clinicians currently managing these patients and for anyone in the future who wants to understand what the state of the art was in 2004. Follicular lymphoma accounts for about one-third of non- Hodgkin’s lymphomas in the United States, making it likely that an individual oncologist will see one to three patients with follicular lymphoma each year. As the authors point out, numerous active agents have been developed for use in patients with follicular lymphoma over the past 5 years and additional promising new therapeutic agents and novel approaches (eg, vaccination) are in the development pipeline.

Positron-emission tomography(PET) and computed tomography(CT) fusion imaging is arapidly evolving technique that is usefulin the staging of non–small-celllung cancer (NSCLC), Hodgkin’s disease,ovarian cancer, gastrointestinalstromal tumors, gynecologic malignancies,colorectal malignancies,and breast cancer. In their article,Rusthoven et al[1] describe the roleof PET-CT in head and neck malignanciesand include a review of allcurrently available literature. Accordingto the authors, PET-CT is usefulfor staging head and neck carcinomasand for target volume delineation duringradiation treatment planning.

Contrast-enhanced breast magnetic resonance imaging (MRI) is arelatively new but increasingly used modality for the detection of breastcancer. MRI has demonstrated utility in identifying additional tumorfoci and extent of disease in patients with known breast cancer. This isespecially useful with invasive lobular carcinoma, which is difficult toevaluate on mammography. MRI has been found to identify the primarytumor in 70% to 86% of cases of occult breast cancer. Contrastenhancedbreast MRI has shown some usefulness in the detection ofresidual cancer following surgery but is limited by postoperative changes.In patients who have undergone neoadjuvant chemotherapy, breast MRIis most accurate in those patients in whom there is little or no responseto chemotherapy. The use of contrast-enhanced breast MRI for breastcancer screening is controversial. It has only been used in a few smallstudies of high-risk patients. The limitations of breast MRI includeuptake in benign lesions and normal tissue, sensitivity for ductal carcinomain situ, cost, and availability. This paper will discuss the uses,benefits, and limitations of contrast-enhanced breast MRI in the stagingand screening of breast cancer.

In this excellent review of breastmagnetic resonance imaging (MRI),Gundry discusses the potential advantagesand disadvantages of magneticresonance in breast cancerscreening and management and givesrecommendations for how it shouldbe applied.

The fusion of 18-fluorodeoxyglucose (FDG) positron-emission tomography(PET) with computed tomography (CT) offers both anatomicand physiologic delineation of head and neck cancers. PET-CT is usefulin the staging of head and neck carcinomas and may identify unsuspecteddistant metastasis that may alter treatment. PET-CT may alsohelp in target volume delineation during radiotherapy (RT) treatmentplanning. Better characterization of the target may improve local controlas well as spare normal tissues from RT sequelae.

The stated aim of Seo’s article isto focus on the diagnosis andmanagement of infections thatcan occur in patients with lung cancer.Most of the studies of infections in cancer patients over the past 4 decadeshave dealt predominantly withopportunistic infections in immunocompromisedindividuals who havelymphoproliferative malignancies.Less attention has been given to infectionsassociated with solid tumors,so a comprehensive review of theproblem in patients with lung canceris greatly needed.

The article by Dr. Seo providesa comprehensive review of theepidemiology, presentation, andtreatment of infection in lung cancerpatients. Infection is a significant causeof morbidity and mortality in cancerpatients, as a consequence of immunologicabnormalities that result from thecancer itself as well as from cytotoxiccancer therapies. Granulocytopenia andlymphocyte dysfunction commonlyoccur following intensive therapy formany solid tumors such as lung cancer,and these cellular deficiencies particularlypredispose patients to certain infections.Respiratory infections arecommon during the course of lung cancer,often as a result of direct effects onthe lung including radiation therapy andtumor burden causing obstruction, especiallywith bronchogenic carcinomasor carcinoid tumors. Postsurgical infections,following biopsy or thoracotomyfor resection, are also common.Infectious complications are problematicfor both patient and oncologistsbecause they may delay treatment andimpair quality of life.

In their manuscript, Ganti et al tackle a very intricate and controversial subject: follicular non-Hodgkin’s lymphoma (NHL). The manuscript attempts to exhaustively cover multiple aspects of the disease, including pathology, prognostic factors, natural history, treatment of early-stage as well as advanced disease, relapsed disease, newer agents, monoclonal antibodies, interferon, radioimmunotherapy, stem cell transplantation, and future directions. To review all these topics thoroughly would almost require a textbook. To meticulously cover all of these aspects in a review article is a nearly impossible task. From my standpoint as a reviewer, to critique this article is an equally complicated task. I will therefore focus on only a few major issues.

Ganti et al present quite an extensive overview of follicular lymphoma, with most of their emphasis on clinical practice. Many of the issues they touch upon demonstrate that we cannot draw firm conclusions about the superiority of various treatments over others, due to a variety of study limitations. These challenges to interpretation include the indolent course of the disease in most patients (and thus the long follow-up needed to draw firm conclusions), the often small number of patients in this category, the retrospective nature of most studies, differences in risk factors, and the relative lack of randomized studies. As is also the case with efficacy, the most beneficial treatment strategy in follicular lymphoma remains to be established.