Nitrogen mustard therapy; use of methyl-bis (beta-chloroethyl) amine hydrochloride and tris (beta-chloroethyl) amine hydrochloride for Hodgkin's disease, lymphosarcoma, leukemia and certain allied and miscellaneous disorders

Cancer nanomedicines: so many papers and so few drugs!

This review identifies a timeline to nanomedicine anticancer drug approval using the business model of inventors, innovators and imitators. By evaluating the publication record of nanomedicine cancer therapeutics we identified a trend of very few publications prior to FDA approval. We first enumerated the publications related to cancer involving polymers, liposomes or monoclonal antibodies and determined the number of citations per publication as well as the number of published clinical trials among the publications. Combining these data with the development of specific nanomedicines, we are able to identify an invention phase consisting of seminal papers in basic science necessary for the development of a specific nanomedicine. The innovation phase includes the first report, the development and the clinical trials involving that nanomedicine. Finally, the imitation phase begins after approval when others ride the wave of success by using the same formulation for new drugs or using the same drug to validate other nanomedicines. We then focused our analysis on nanomedicines containing camptothecin derivatives, which are not yet approved including two polymers considered innovations and one liposomal formulation in the imitation phase. The conclusion that may be drawn from the analysis of the camptothecins is that approved drugs reformulated in polymeric and liposomal cancer nanomedicines have a more difficult time navigating through the approval process than the parent molecule. This is probably due to the fact that for most currently approved drugs, reformulating them in a nanocarrier provides a small increase in performance that large pharmaceutical companies do not consider being worth the time, effort and expense of development. It also appears that drug carriers have a more difficult path through the clinic than monoclonal antibodies. The added complexity of nanocarriers also deters their use to deliver new molecular entities. Thus, the new drug candidates that might be most improved by drug delivery in nanocarriers are not formulated in this fashion.

Cooperative group trials in pediatric oncology: the surgeon's role

The early history of the pediatric cooperative group trials is reviewed, and the surgeons who played a critical role in their formation are discussed. The vital information provided from the tumor specimens submitted as part of the protocols is presented, as well as how this information advanced our management of infants and children treated on current protocols of the Children's Oncology Group. Finally, a survey of the surgeons currently active in the clinical trials defined the "critical lessons" learned from the sequence of protocols by the cooperative groups which have advanced our surgical treatment of patients today.

Topical chemotherapy in cutaneous T-cell lymphoma: positive results of a randomized, controlled, multicenter trial testing the efficacy and safety of a novel mechlorethamine, 0.02%, gel in mycosis fungoides

OBJECTIVE

To evaluate the efficacy and safety of a novel mechlorethamine hydrochloride, 0.02%, gel in mycosis fungoides. DESIGN Randomized, controlled, observer-blinded, multicenter trial comparing mechlorethamine, 0.02%, gel with mechlorethamine, 0.02%, compounded ointment. Mechlorethamine was applied once daily for up to 12 months. Tumor response and adverse events were assessed every month between months 1 and 6 and every 2 months between months 7 and 12. Serum drug levels were evaluated in a subset of patients.

SETTING

Academic medical or cancer centers.

PATIENTS

In total, 260 patients with stage IA to IIA mycosis fungoides who had not used topical mechlorethamine within 2 years and were naive to prior use of topical carmustine therapy.

MAIN OUTCOME MEASURES

Response rates of all the patients based on a primary clinical end point (Composite Assessment of Index Lesion Severity) and secondary clinical end points (Modified Severity-Weighted Assessment Tool and time-to-response analyses).

RESULTS

Response rates for mechlorethamine gel vs ointment were 58.5% vs 47.7% by the Composite Assessment of Index Lesion Severity and 46.9% vs 46.2% by the Modified Severity-Weighted Assessment Tool. By the Composite Assessment of Index Lesion Severity, the ratio of gel response rate to ointment response rate was 1.23 (95% CI, 0.97-1.55), which met the prespecified criterion for noninferiority. Time-to-response analyses demonstrated superiority of mechlorethamine gel to ointment (P< .01). No drug-related serious adverse events were seen. Approximately 20.3% of enrolled patients in the gel treatment arm and 17.3% of enrolled patients in the ointment treatment arm withdrew because of drug-related skin irritation. No systemic absorption of the study medication was detected.

CONCLUSION

The use of a novel mechlorethamine, 0.02%, gel in the treatment of patients with mycosis fungoides is effective and safe.

TRIAL REGISTRATION

clinicaltrials.gov Identifier:NCT00168064.

Point/counterpoint: early-stage Hodgkin lymphoma and the role of radiation therapy

The results of recent clinical trials for the management of limited-stage Hodgkin lymphoma have led to considerable debate, especially regarding the role of radiation therapy. This review highlights those recent trials and provides perspectives regarding their interpretation from a radiation oncologist and a hematologist. The trial protocol is available at http://www.nejm.org/doi/suppl/10.1056/NEJMoa1111961/suppl_file/nejmoa1111961_protocol.pdf.

Point/counterpoint: early-stage Hodgkin lymphoma and the role of radiation therapy

The results of recent clinical trials for the management of limited-stage Hodgkin lymphoma have led to considerable debate, especially regarding the role of radiation therapy. This review highlights those recent trials and provides perspectives regarding their interpretation from a radiation oncologist and a hematologist. The trial protocol is available at http://www.nejm.org/doi/suppl/10.1056/NEJMoa1111961/suppl_file/nejmoa1111961_protocol.pdf.

The mechanism of guanine alkylation by nitrogen mustards: a computational study

The thermodynamics and kinetics for the monofunctional binding of nitrogen mustard class of anticancer drugs to purine bases of DNA were studied computationally using guanine and adenine as model substrates. Mechlorethamine and melphalan are used as model systems in order to better understand the difference in antitumor activity of aliphatic and aromatic mustards, respectively. In good agreement with experiments that suggested the accumulation of a reactive intermediate in the case of mechlorethamine, our model predicts a significant preference for the formation of corresponding aziridinium ion for mechlorethamine, while the formation of the aziridinium ion is not computed to be preferred when melphalan is used. Two effects are found that contribute to this difference. First, the ground state of the drug shows a highly delocalized lone pair on the amine nitrogen of the melphalan, which makes the subsequent cyclization more difficult. Second, because of the aromatic substituent connected to the amine nitrogen of melphalan, a large energy penalty has to be paid for solvation. A detailed study of energy profiles for the two-step mechanism for alkylation of guanine and adenine was performed. Alkylation of guanine is ∼6 kcal mol(-1) preferred over adenine, and the factors contributing to this preference were explained in our previous study of cisplatin binding to purine bases. A detailed analysis of energy profiles of mechlorethamine and melphalan binding to guanine and adenine are presented to provide an insight into rate limiting step and the difference in reactivity and stability of the intermediate in both nitrogen mustards, respectively.

Sidney Farber and the treatment of childhood acute lymphoblastic leukemia with a chemotherapeutic agent

Acute lymphoblastic leukemia (ALL) is the most common malignancy affecting children accounting for approximately 30% of childhood cancers, which was uniformly fatal before the advent of effective chemotherapy. In this historical note, the fundamental contribution of Sidney Farber to the treatment of ALL by using, for the first time, aminopterin-a chemotherapeutic agent-has been recognized.

Cancer chemotherapy: a critical analysis of its 60 years of history

Chemotherapy has already proven widely effective in the treatment of cancer, occupying a prominent place in the current therapeutic arsenal. However, in recent years, there has been a plateau in the evolution of the clinical results obtained with this modality treatment. In some cases, the limitations of chemotherapy observed during the early days still apply. These facts forced us to do a thorough analysis of what happened in the past 60years. We have observed that each major advance obtained in this field was based on empirical clinical observations. We thus believe that the current results of old or new agents can only be improved by understanding the natural history of each specific cancer subtype at the clinical level and by overcoming the physiological barriers involved in chemotherapy failure. This strategy will surely allow us to enlarge the list of curable cancers by chemotherapy.

[Alkylating agents]

With the approval of mechlorethamine by the FDA in 1949 for the treatment of hematologic malignancies, alkylating agents are the oldest class of anticancer agents. Even though their clinical use is far beyond the use of new targeted therapies, they still occupy a major place in specific indications and sometimes represent the unique option for the treatment of refractory diseases. Here, we are reviewing the major classes of alkylating agents and their mechanism of action, with a particular emphasis for the new generations of alkylating agents. As for most of the chemotherapeutic agents used in the clinic, these compounds are derived from natural sources. With a complex but original mechanism of action, they represent new interesting alternatives for the clinicians, especially for tumors that are resistant to conventional DNA damaging agents. We also briefly describe the different strategies that have been or are currently developed to potentiate the use of classical alkylating agents, especially the inhibition of pathways that are involved in the repair of DNA lesions induced by these agents. In this line, the development of PARP inhibitors is a striking example of the recent regain of interest towards the "old" alkylating agents.

Assessment of the evolution of cancer treatment therapies

Cancer therapy has been characterized throughout history by ups and downs, not only due to the ineffectiveness of treatments and side effects, but also by hope and the reality of complete remission and cure in many cases. Within the therapeutic arsenal, alongside surgery in the case of solid tumors, are the antitumor drugs and radiation that have been the treatment of choice in some instances. In recent years, immunotherapy has become an important therapeutic alternative, and is now the first choice in many cases. Nanotechnology has recently arrived on the scene, offering nanostructures as new therapeutic alternatives for controlled drug delivery, for combining imaging and treatment, applying hyperthermia, and providing directed target therapy, among others. These therapies can be applied either alone or in combination with other components (antibodies, peptides, folic acid, etc.). In addition, gene therapy is also offering promising new methods for treatment. Here, we present a review of the evolution of cancer treatments, starting with chemotherapy, surgery, radiation and immunotherapy, and moving on to the most promising cutting-edge therapies (gene therapy and nanomedicine). We offer an historical point of view that covers the arrival of these therapies to clinical practice and the market, and the promises and challenges they present.

Mechanism of cell adaptation: when and how do cancer cells develop chemoresistance?

Chemotherapy treatments are considered essential tools to defeat cancer progression and dissemination to improve patients' quality of life and survival. Although most malignancies initially respond to chemotherapeutic treatments, after an unpredictable period, tumor cells develop mechanisms of resistance to the treatment. Different cell compartments are involved in the mechanism of chemoresistance, and multiple mechanisms can be activated by single cells at different times of the cancer progression. Alteration of drug metabolism, derangement of intracellular pathways' signaling, cross-talk between different membrane receptors, and modification of apoptotic signaling and interference with cell replication are all mechanisms that the cell uses to overcome the effect of pharmacological compounds.In this review, we describe different adaptation, mostly at the level of the proteome, which cancer cells use to develop resistance to cancer treatment.

The 6-MP versus placebo clinical trial in acute leukemia

Background This article gives the status of clinical cancer research in the 1950's–1960's and tells the story of the development and conduct of the 6-mercaptopurine (6-MP) versus placebo clinical trial in acute leukemia through the initiation, design, conduct and analysis stages, with emphasis on the ethical aspects of randomizing patients to 6-MP or placebo when in remission.

Purpose The specific objective was to compare the lengths of remission for patients receiving 6-MP or placebo after achieving complete or partial remission from steroid treatment.

Methods A randomized, double-blind, placebo controlled sequential study was conducted in which patients were paired by remission status at each of the eleven institutions participating in the study, and randomized to 6-MP or placebo within each pair of patients. A preference for 6-MP or placebo was recorded depending on which patient in the pair had the longer remission. The preferences were plotted according to a restricted sequential procedure devised by Peter Armitage and, depending on which boundary of the design was crossed, a statistically significant difference could be declared favoring 6-MP, placebo or no preference.

Conclusions The trial established the efficacy of 6-MP for maintaining longer remissions in acute leukemia and led to the concept of 'adjuvant chemotherapy', namely that patients with minimal disease have a substantially better response to chemotherapy than patients with advanced disease, a concept that has been followed in many other forms of cancer. Statistically, the fact that many patients were still in remission when the study was stopped (i.e. the length of remission data for these patients was 'right censored') led to the development of a generalized Wilcoxon test and was an important influence on Cox's development of the proportional hazards model. The trial had an innovative design in the early 1960's and has been an important influence on subsequent clinical research in cancer and statistical research in survival analysis.

DNA interstrand crosslink repair and cancer

Interstrand crosslinks (ICLs) are highly toxic DNA lesions that prevent transcription and replication by inhibiting DNA strand separation. Agents that induce ICLs were one of the earliest, and are still the most widely used, forms of chemotherapeutic drug. Only recently, however, have we begun to understand how cells repair these lesions. Important insights have come from studies of individuals with Fanconi anaemia (FA), a rare genetic disorder that leads to ICL sensitivity. Understanding how the FA pathway links nucleases, helicases and other DNA-processing enzymes should lead to more targeted uses of ICL-inducing agents in cancer treatment and could provide novel insights into drug resistance.

O. Harold Warwick: Canada's first medical oncologist

O. Harold Warwick graduated in medicine from McGill University as a gold medalist and Rhodes Scholar in 1940. After World War II, he started postgraduate training in Montreal, and in 1946, he began studying the newly described drug treatment of cancer in London, England. There he carried out the first study of nitrogen mustard in a group of adult patients with a non-hematologic solid tumour, lung cancer. After a brief period of practice in Montreal, he moved in 1948 to Toronto, where he became executive director of the Canadian Cancer Society and the National Cancer Institute of Canada. Simultaneously, he joined the staff of Toronto General Hospital and its Radiotherapy Institute, where he became the first physician-oncologist to provide medical care and administer anticancer drugs in a Canadian cancer centre. In 1958, the new Princess Margaret Hospital opened in Toronto; Warwick became its first chief physician, responsible for clinical drug trials. Here he carried out his best known clinical study-the use of vinblastine sulphate in patients with Hodgkin lymphoma. From 1961 to 1971, he served as dean and then vice-president Health Sciences at the University of Western Ontario. He returned to the practice of medical oncology from 1972 to 1980 at the London Cancer Clinic, after which he had a long and productive retirement. He died in October 2009. Although the specialty was not named until the latter years of his career, Harold Warwick satisfied all the criteria for and was undoubtedly Canada's first medical oncologist.

Using synthetic DNA interstrand crosslinks to elucidate repair pathways and identify new therapeutic targets for cancer chemotherapy

Many cancer chemotherapeutic agents form DNA interstrand crosslinks (ICLs), extremely cytotoxic lesions that form covalent bonds between two opposing DNA strands, blocking DNA replication and transcription. However, cellular responses triggered by ICLs can cause resistance in tumor cells, limiting the efficacy of such treatment. Here we discuss recent advances in our understanding of the mechanisms of ICL repair that cause this resistance. The recent development of strategies for the synthesis of site-specific ICLs greatly contributed to these insights. Key features of repair are similar for all ICLs, but there is increasing evidence that the specifics of lesion recognition and synthesis past ICLs by DNA polymerases are dependent upon the structure of ICLs. These new insights provide a basis for the improvement of antitumor therapy by targeting DNA repair pathways that lead to resistance to treatment with crosslinking agents.

The birth of the subspecialty of medical oncology and examples of its early scientific foundations

"Passion is not accepting defeat."--Emil Frei III. In the early 1950s, an experimental and clinical program characterized by unique cross-fertilization was developed. The clinical importance of experimental animal models in drug screening and in establishing key chemotherapy concepts and the role of the pioneers of medical oncology in the design of the various phases of drug trials, using childhood acute leukemia and breast cancer as models, are discussed. Over a short time and with only a few drugs, principles of chemotherapy were laid out, which led to cures in such diseases as childhood acute leukemia and Hodgkin's disease and to improved disease-free survival in breast cancer. It is these and other achievements that paved the way to medical oncology. At the instigation of the American Society of Clinical Oncology (ASCO), the American Board of Internal Medicine made inquiries about a subspecialty in oncology. ASCO and B. J. Kennedy, MD, played key roles in the events leading to the official recognition of medical oncology as a new subspecialty of internal medicine in 1972.

A history of cancer chemotherapy

The use of chemotherapy to treat cancer began at the start of the 20th century with attempts to narrow the universe of chemicals that might affect the disease by developing methods to screen chemicals using transplantable tumors in rodents. It was, however, four World War II-related programs, and the effects of drugs that evolved from them, that provided the impetus to establish in 1955 the national drug development effort known as the Cancer Chemotherapy National Service Center. The ability of combination chemotherapy to cure acute childhood leukemia and advanced Hodgkin's disease in the 1960s and early 1970s overcame the prevailing pessimism about the ability of drugs to cure advanced cancers, facilitated the study of adjuvant chemotherapy, and helped foster the national cancer program. Today, chemotherapy has changed as important molecular abnormalities are being used to screen for potential new drugs as well as for targeted treatments.

Development history and concept of an oral anticancer agent S-1 (TS-1): its clinical usefulness and future vistas

Dushinsky et al. left a great gift to human beings with the discovery of 5-fluorouracil (5-FU). Approximately 50 years have elapsed from that discovery to the development of S-1 (TS-1^®). The concept of developing an anticancer agent that simultaneously possesses both efficacy-enhancing and adverse reaction-reducing effects could be achieved only with a three-component combination drug. S-1 is an oral anticancer agent containing two biochemical modulators for 5-FU and tegafur (FT), a metabolically activated prodrug of 5-FU. The first modulator, 5-chloro-2,4-dihydroxypyridine (CDHP), enhances the pharmacological actions of 5-FU by potently inhibiting its degradation. The second modulator, potassium oxonate (Oxo), localizing in mucosal cells of the gastrointestinal (GI) tract after oral administration, reduces the incidence of GI toxicities by suppressing the activation of 5-FU in the GI tract. Thus, S-1 combines FT, CDHP and Oxo at a molar ratio of 1:0.4:1. In 1999–2007, S-1 was approved for the treatment of the following seven cancers: gastric, head and neck, colorectal, non-small cell lung, breast, pancreatic and biliary tract cancers. ‘S-1 and low-dose cisplatin therapy’ without provoking Grade 3 non-hematologic toxicities was proposed to enhance its clinical usefulness. Furthermore, ‘alternate-day S-1 regimen’ may improve the dosing schedule for 5-FU by utilizing its strongly time-dependent mode of action; the former is characterized by the low incidences of myelotoxicity and non-hematologic toxicities (e.g. ≤Grade 1 anorexia, fatigue, stomatitis, nausea, vomiting and taste alteration). These two approaches are considered to allow long-lasting therapy with S-1.

Resistance to chemotherapy: new treatments and novel insights into an old problem

Resistance to cancer chemotherapeutic treatment is a common phenomenon, especially in progressive disease. The generation of cellular models of drug resistance has been pivotal in unravelling the main effectors of resistance to traditional chemotherapy at the molecular level (i.e. intracellular drug inactivation, detoxifying systems, defects in DNA repair, apoptosis evasion, membrane transporters and cell adhesion). The development of targeted therapies has also been followed by resistance, reminiscent of an evolutionary arms race, as exemplified by imatinib and other BCR-ABL inhibitors for the treatment of chronic myelogenous leukaemia. Although traditionally associated with the last stages of the disease, recent findings with minimally transformed pretumorigenic primary human cells indicate that the ability to generate drug resistance arises early during the tumorigenic process, before the full transformation. Novel technologies, such as genome profiling, have in certain cases predicted the outcome of chemotherapy and undoubtedly have tremendous potential for the future. In addition, the novel cancer stem cell paradigm raises the prospect of cell-targeted therapies instead of treatment directed against the whole tumour.

Battling the hematological malignancies: the 200 years' war

The delineation of the hematological malignancies began near the end of the first third of the 19th century with the recognition of the similarity among cases with lymph node tumors and an enlarged spleen (Hodgkin's disease). Descriptions of chronic and acute leukemia and myeloma followed thereafter. In the first years of the 20th century the discovery of x-radiation permitted palliative orthovoltage radiation therapy of Hodgkin's disease. Following World War II, legitimate drug therapy for the hematological malignancies was introduced: nitrogen mustard, adrenocorticotropic hormone and cortisone acetate, and anti-folic acid derivatives, initially aminopterin. Today, about 14 classes of drugs (different mechanisms of action) and >50 individual agents are being used, with others under study. Several examples of agents targeting specific transcription factors or oncoproteins have been introduced. Despite remarkable progress, including the ability to cure acute leukemia in about 70% of children, cure several genetic variants of acute myelogenous leukemia in younger adults, cure some cases of lymphoma in children and younger adults, and induce prolonged remission in many affected persons, the majority of patients face an uncertain outcome and shortened life. Thus, we have much to do in the next several decades. The significant hurdles we must overcome include: the apparent infrequency of an exogenous cause that can be avoided, the exponential increase in incidence rates with age and the dramatic negative effect of aging on the results of treatment, the challenge of one trillion or more disseminated cancer cells among which are a smaller population of cancer stem cells, the profound genetic diversity of the hematological malignancies (apparently hundreds of unique genetic primary lesions), the redundant growth and survival pathways defining the cancer phenotype, the decreasing market for pharmaceutical companies as therapy becomes more specific (fewer target patients) and drug development costs become more expensive, and the significant negative long-term effects of current therapy on both children and adults. These challenges will be gradually overcome, if we (a) develop new models of cooperation among academia, industry, and government, (b) continue the growth of international participation in cancer research (more keen minds to the task), and (c) convince the governments of the world, including that of the U.S., that an investment in minimizing the effects of cancer is as important as defending against other threats to the welfare and longevity of their citizens.

Single-molecule detection of nitrogen mustards by covalent reaction within a protein nanopore

Mustards, including sulfur mustards and nitrogen mustards, form a class of cytotoxic, vesicant chemical warfare agents. Mustards have also been used to treat cancer and played a vital role in the development of chemotherapy. Additionally, because of their destructive properties, ease of synthesis, and the lack of effective antidotes, mustards are unquestionably terrorist threats. Therefore, quick and convenient detection of mustards is a critical issue. In the present study, we achieved detection of various mustards on the basis of their chemical reactivity by using engineered alpha-hemolysin (alphaHL) protein pores as sensor elements. We describe four classes of reactions for detecting mustards. These reactions occur between mustards and thiol groups contributed by cysteine side-chains within the lumen of the alphaHL pore or on an internal molecular adapter. The approach is quick and straightforward. It can confirm the existence of mustards in as little as 10 min at 50 microM or lower.

Hodgkin's Lymphoma: The Role of Radiation in the Modern Combined Strategies of Treatment

A history of the treatment of Hodgkin's disease with radiation therapy and chemotherapy is presented. Studies are reviewed examining treatment for favorable and unfavorable presentation of stage I-II disease, stage III-IV disease, and relapsed disease. In this era of combined-modality therapy we have reached the point of near-total conquest of Hodgkin's lymphoma, but challenges remain. Directions for future research are discussed.

The contribution of Gianni Bonadonna to the history of chemotherapy

The history of cancer chemotherapy and of the discipline of medical oncology has been that of drug discovery. The pioneering discoveries of the early days of chemotherapy have allowed the development of a paradigm for drug discovery that persists, with modifications to the present day. This review article summarizes the seminal work of the Italian scientist Gianni Bonadonna on the treatment of breast cancer and Hodgkin's disease.

Chromatin as a target for the DNA-binding anticancer drugs

Chemotherapy has been a major approach to treat cancer. Both constituents of chromatin, chromosomal DNA and the associated chromosomal histone proteins are the molecular targets of the anticancer drugs. Small DNA binding ligands, which inhibit enzymatic processes with DNA substrate, are well known in cancer chemotherapy. These drugs inhibit the polymerase and topoisomerase activity. With the advent in the knowledge of chromatin chemistry and biology, attempts have shifted from studies of the structural basis of the association of these drugs or small ligands (with the potential of drugs) with DNA to their association with chromatin and nucleosome. These drugs often inhibit the expression of specific genes leading to a series of biochemical events. An overview will be given about the latest understanding of the molecular basis of their action. We shall restrict to those drugs, synthetic or natural, whose prime cellular targets are so far known to be chromosomal DNA.

Joe Burchenal and the birth of combination chemotherapy

When Joe Burchenal started studying medicine at the University of Pennsylvania in 1934, antibiotics had not been discovered and the survival of patients diagnosed with acute leukaemia was < 4 months. By the time he retired in 1983, 58% of children with acute lymphoblastic leukaemia survived 5 years with the majority being cured of their disease. His early work in infectious diseases and antimicrobials equipped him well, both clinically and scientifically. The approach to developing antibiotics to conquer previously incurable infection was an inspiration and model for his pioneering work when searching for drugs with activity against cancer. Trials of sequential and then combination chemotherapy followed. Success in treating lymphoid malignancies in children led him to develop treatment regimens for other more resistant cancers, and as an advocate of collaborative working he introduced multimodal therapy to tackle bulky or metastatic cancers, replacing inevitable relapse with a chance of true cure.