Principios Del Tratamiento Del Cancer Por Cirugia

7/30/2019 Principios Del Tratamiento Del Cancer Por Cirugia

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2006 Elsevier Ltd70SURGERY 24:2

Surgery has been the cornerstone of treatment of patients with

solid cancers for more than 100 years. For most of this time, there

have been few changes in the technical aspects of surgery, with

more or less radical procedures gaining or losing favour periodi-

cally. Recently, there has been a resurgence of interest in a more

radical, anatomical approach, combined with increasingly complex

procedures to preserve function or appearance. The increasing

adaptation of radical surgery for recurrent and metastatic disease

is also extending the role of surgery in cancer treatment.Traditionally, general surgeons provided the service for a wide

range of patients with cancer. Subspecialization in general sur-

gery (see Black, CROSS REFERENCES) started to appear during

the 1980s and early 1990s. The publication of the CalmanHine

report provided a major impetus to subspecialization into separate

disciplines (e.g. breast, gastrointestinal tract (upper and lower),

hepatopancreatobiliary). Some of these subspecialties deal almost

exclusively with surgery for malignancy (e.g. breast), while others

contain a substantial proportion of patients with non-malignant

disease who may present with almost identical symptoms.

Services have been extensively reconfigured to meet the needs

of symptomatic patients who are found to have cancer. Initiatives

in the UK (e.g. two-week rule for initial appointment, fast-trackdiagnostic clinics) are designed to streamline the pathway for

those patients recognized by their GPs to be at high risk of malig-

nancy. These patients must now begin definitive treatment within

62 days of referral. Paradoxically, this may delay the assessment

and diagnosis of patients with malignancy whose presentation is

not regarded as suspicious, and future initiatives must streamline

access to treatment for all patients found to have cancer, regardless

of the referral route. This review focuses on services in the UK.

Organization of cancer services

A major configuration of services for patients with solid cancers

was initiated after the publication of the CalmanHine report; thisfundamentally affected the way surgeons worked and trained.

Multidisciplinary teams ensure that patients are treated by re-

cognized specialists in accordance with accredited evidence-based

guidelines. These guidelines (typically produced by the National

Institute for Clinical Exellence) define how and where patients

should be treated. This has resulted in centralized surgical serv-

ices for many forms of cancer (e.g. upper gastrointestinal tract,

hepatobiliary, urological, some gynaecological malignancies)

while others are treated in Cancer Centres and Cancer Units (e.g.

breast, colorectal).

The quality of the evidence is questionable, but it is widely

accepted that specialist teams dealing with larger caseloads provide

optimal care for most cancer patients. In addition to increasing

expertise of team members, specialization and centralization

results in the most efficient use of resources. This advantage must

be balanced by the inconvenience for patients and carers travellinggreater distances and the potential for deskilling and demotivat-

ing staff in Cancer Units no longer contributing to the treatment

of certain categories of patients. The effect of these changes on

surgical services has yet to be realized.

Role of surgery in cancer treatment

Surgery in cancer diagnosis

Improvements in diagnostic imaging, cytology and interpretation of

wide-bore needle biopsies (core biopsies) have markedly reduced

the need for open biopsies and diagnostic surgery. Image-guided

core biopsy using ultrasound or CT is common and permits accu-

rate diagnosis and treatment planning.Biopsies most centres use core biopsy for the diagnosis of

malignancy because much more information can be gained from

a core biopsy compared to fine-needle aspiration cytology. Core

biopsy can reliably diagnose invasive disease, whereas cytology

cannot distinguish invasive from non-invasive malignancy. Estima-

tion of the status of the oestrogen receptor can be done on breast

core biopsies, as can the identification of tumour type; tumour

grade may be less reliably ascertained by this technique.

Patients presenting with enlarged cervical lymph nodes are

frequently referred to general surgeons who may carry out an

excision biopsy as the initial investigation; this practice should not

be used. A needle biopsy may help distinguish those patients with

lymphoma from those with secondary epithelial neoplasia. Excisionbiopsy for the accurate diagnosis of lymphoma may be indicated

after consultation with a haematological oncologist. Patients with

suspected malignancy of the upper aerodigestive tract should be

cared for by a surgeon with a specialist interest in malignancies

of the head and neck. Poorly planned excision biopsies of meta-

static nodes from malignancies of the upper aerodigestive tract are

associated with an increased rate of failure of local control after

further surgery.

Laparoscopy is used in diagnosis and staging of intra-abdominal

malignancy and can dramatically reduce the rate of open and

close laparotomy.

Curative surgeryEarly detection of cancer: the most important factor determining

the likelihood of cure for patients with cancer is the stage of the

disease at presentation. The early detection of cancer depends on

a number of factors, including:

public education and awareness

access to and accuracy of diagnostic services in primary and

secondary care

introduction of effective screening programmes (Figure 1).

Screening programmes a major feature of the NHS Breast

Screening programme is the rigorous audit and quality assurance

that has been in place since its inception. This resulted in the

performance of individual surgeons being compared to standards

Principles of cancertreatment by surgeryMalcolm Reed FRCS

Malcolm Reedis a Professor of Surgical Oncology at the Academic

Surgical Oncology Unit, Royal Hallamshire Hospital, Sheffield, UK.


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and targets. Areas of weakness such as the quality of axillary node

surgery were identified early in the programme and there has been

a steady improvement in performance in this area. Several of the

targets have been raised in response to improved performance. The

method of quality assurance used in the screening programme hasbeen introduced for patients with symptomatic breast disease and

similar models are in place for other malignancies as part of peer

review of Cancer Centres and Cancer Units.

Plans are well advanced for the introduction of programmes

for the early detection of colorectal carcinoma based on stud-

ies confirming the efficacy of colonic support screening of the

asymptomatic population (see Scholefield and Whynes, CROSS

REFERENCES). Many clinicians run ad hocscreening programmes

for patients with a family history of malignancy, such as breast

or colorectal cancer, based on the well-recognized increased risk

to individuals with a number of close relatives affected by these

conditions. There is no conclusive evidence that inclusion in such

programmes results in a reduction of mortality, but evidence from anumber of audits of family history clinics in breast cancer suggest

that such programmes can detect disease at an earlier stage and at

a greater incidence than would be expected. Attempts to launch a

national controlled trial of screening for those with a family his-

tory of breast cancer have been unsuccessful. Screening in other

groups of patients at high risk of malignancy (e.g. ulcerative colitis,

Barretts oesophagus) have not shown a reduced mortality from

the associated malignancy. Studies of endoscopic screening of

patients with Barretts oesophagus have indicated that this may

result in detection of oesophageal cancer at an earlier stage, when

it is more likely to be curable by surgery.

Staging: the introduction of preoperative treatments such aschemotherapy (see page 66) and radiotherapy (see page 62) for

patients with local disease of borderline operability, and alternative

methods of palliation for those with incurable metastatic disease,

have led to the recognition of the importance of preoperative

staging. For instance, it was previously common practice not to

investigate patients with colorectal cancer for liver metastases

because the primary tumour required excision and therefore man-

agement would not be altered. This approach failed to recognize

the devastating effect of being told that metastatic disease had

been diagnosed at an operation where the patient was hoping for

cure. The introduction of alternatives for palliation (e.g. endo-

scopic stenting) has resulted in meaningful alternative choices for

patients, and therefore staging is essential.

The role of preoperative radiotherapy and chemotherapy in

rectal and oesophageal cancer is rapidly increasing. Swedish

studies of preoperative radiotherapy in rectal cancer indicate that

local recurrence rates can be reduced dramatically, but this results

in a local recurrence rate only equivalent to the best that can be

achieved by surgery alone (about 5%).

Staging systems based on clinical observation alone (e.g. tra-ditional TNM, Manchester staging for breast cancer) are becom-

ing obsolete due to improvements in imaging and pathological

staging systems. The local staging of most cancers is now based

entirely on histological features, whereas the presence or absence

of distant metastases is dependent on imaging. The influence of

histopathological assessment in clinical outcomes is subtle and

needs to be recognized when interpreting and comparing trends in

cancer survival. This effect, known as stage migration can result

in apparent improved survival for patients due to more accurate

staging. For example, a more rigorous examination of the status of

lymph nodes in patients with rectal cancer results in more patients

being allocated into the Dukes C group; this results in an improved

survival for the patients classified as Dukes B, due to the exclu-sion of some patients with more advanced disease. The inclusion

of patients with minimal involvement of the lymph nodes in the

Dukes C group also results in improved overall survival for these

patients. Likewise, the introduction of more sophisticated tech-

niques for evaluating distant metastases (e.g. improved resolution

of ultrasound scanner, use of CT or MRI) increases the detection

of minimal metastatic disease, with a similar effect on the survival

figures. The detection of micro-metastases in lymph nodes with the

aid of immunohistochemistry or molecular pathology techniques

has led to the identification of patients with minimal metastatic

disease. Prognosis and adjuvant treatment for these patients, who

typically have breast cancer, is controversial, with no clear evidence

of the effect of this finding on outcome.In terms of cancer outcomes, the most important statistic is

overall disease-specific mortality in the population. This epi-

demiological data depend on the completeness and accuracy of

cancer registration and death certification. Postmortem studies of

the accuracy of death certification indicate that a significant pro-

portion of clinical diagnoses of cause of death are inaccurate and

epidemiological data on disease outcomes can also be flawed.

Curative surgery for primary cancer: there are widespread vari-

ations in the surgical management of individual types of cancer.

This is shown by the different mastectomy rates for breast cancer,

and the variation in the formation of permanent stomas in patients

with rectal cancer. Certain principles can be applied to the surgicaltreatment of cancer with curative intent (Figure 2).

Surgery and adjuvant therapy: the advent of multidisciplinary

team meetings for common cancers ensures that the involvement

of clinical and medical oncologists is introduced early into the care

of cancer patients, before surgery and again at the time of review

of the histopathological results of surgery. This has facilitated adju-

vant therapies before and after definitive surgery. There has been

a major increase in the use of adjuvant chemotherapy in cancer

of the breast and gastrointestinal tract, as well as radiotherapy in

rectal cancer, and a combination of chemotherapy and radiotherapy

in oesophageal cancer.

Prerequisites for a successful screening programme

The disease should be curable and early detection should

increase the chance of cure

The diagnostic test should be acceptable to the target

population

The disease should be sufficiently common The screening test should have acceptable sensitivity and

specificity

Resources (skills and facilities) should be available to allow

implementation for the entire target population

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Postoperative care: early postoperative morbidity resulting from

the complications of surgery and suboptimal management in the

perioperative period contributes to the mortality associated with

cancer treatment. A significant improvement in outcome may be

seen if this problem could be reduced, but this would require: an increase in the availability of HDU and ICU facilities

a more active preoperative optimization of patients before major

surgery

an increased awareness of the importance of postoperative fluid

balance and the early detection of serious complications (e.g.

anastomotic breakdown).

Significant resources are required to improve these aspects of

patient care. Studies have indicated that a substantial proportion

of patients admitted as emergencies with colorectal cancer have

been referred as elective patients or are in the process of being

worked up for surgery; this group of emergency patients carry a

high risk of mortality compared to patients admitted for elective

surgery. The introduction of targets to accelerate the referral anddiagnostic process and the potential effect of screening could

have a substantial effect on the mortality associated with surgery

for colorectal cancer; a similar situation may exist with cancer of

the upper gastrointestinal tract and oesophagus. The realization

of this benefit depends on the accuracy of the referral and rapid

diagnosis of malignancy.

Curative surgery for metastasis: in some circumstances, patients

with metastatic disease can undergo further surgery with a

reasonable prospect for cure. For instance, hepatic resection for

liver metastases from colorectal cancer has become widespread.

The traditional indications have been challenged and, in many

Cancer Centres, the indications for surgery are purely technical,

whereby the most patients with resectable disease may be offered

such treatment. In experienced hands, this procedure is associ-

ated with a low morbidity and mortality. This is an area of rapid

expansion in service demand given the frequency of colorectal

cancer in the population and the fact that >50% will develop

liver metastases.

A further area where resection of metastases is possible andcan result in long-term survival is sarcoma surgery, where surgery

of lung metastases has been practised for some time. Sarcomas

are rare tumours and this type of surgery is uncommon. The pos-

sibility of further curative surgery for diseases such as colorectal

cancer and sarcoma has greatly altered the way these patients

are followed up. It is routine practice for patients with colorectal

cancer to have ultrasound of the liver and regular monitoring of

the concentration of carcinoembryonic antigen in their serum.

Patients with soft-tissue sarcomas should be followed-up in dedi-

cated clinics where imaging for lung metastases can be scheduled

and access to thoracic surgical expertise facilitated.

There is no evidence for benefit in the follow-up of patients

with previous breast malignancy, and this follow-up could bedone by GPs. However, it is now a requirement for hospitals to

produce long-term survival statistics after the treatment of all

malignancies, and the only reliable way to collect this data is for

patients to be followed up at hospital; this will remain the case

until improvements in sharing information technology in the

NHS are implemented. For patients with previous breast cancer,

a further aspect of follow-up is the detection of new malignan-

cies. Most of these could be detected by mammographic screening

alone but, for patients previously treated by conservation surgery,

clinical examination, ultrasound and MRI imaging are required

to distinguish postoperative fibrosis from recurrence. The recent

publication of clinical trial data indicating benefit from ongoing

endocrine therapy beyond the standard five years of tamoxifentreatment may also result in patients continuing hospital-based

follow-up for a further three years at least.

Reconstructive surgery

Oncoplastic surgery has become increasingly recognized, particu-

larly in breast surgery. Plastic and reconstructive surgeons have

traditionally provided the surgical input for a number of cancer

subtypes (e.g. large skin cancers, some cancers of the head and

neck, delayed reconstruction after surgery for breast cancer). Most

surgical teams have close links with reconstructive surgeons in

the specialized field of soft-tissue sarcoma surgery.

The major cause of psychological distress in cancer patients is

coping with the diagnosis and the possible outcome (see Medicaland psychlogical effects of palliative care, page 53). Studies sug-

gest that women who undergo breast conservation have improved

body image compared to patients undergoing mastectomy or

mastectomy with immediate reconstruction. In terms of overall

psychological outcome and social adjustment, there is little evi-

dence of difference between patients treated by mastectomy or

mastectomy and reconstruction.

However, the altered body image associated with mastectomy

and the inconvenience of an external breast prosthesis contribute

to psychological distress. A rapid increase in primary reconstruc-

tive surgery for patients undergoing mastectomy and wide local

excision for breast cancer has been seen recently in many centres.

Surgical treatment of cancer with curative intent

Patient care should be undertaken by a multidisciplinary team

comprising surgeons, pathologists, radiologists, oncologists

and specialist nurses.

Macroscopic clearance of disease should be achieved

wherever possible. The surgery is classified as palliative if thisis not achieved.

Resection margins should be wide if there is a danger of

microscopic infiltration.

Dissection of lymph nodes does not improve survival, but

may yield valuable information for prognosis and selection

of adjuvant therapy in patients with several types of cancer.

Sentinel node biopsy permits the restriction of axillary surgery

in breast cancer and, potentially, melanoma patients to those

with proven nodal disease. This reduces the unnecessary

morbidity associated with negative lymph node clearance

while ensuring good local control in patients with node

involvements.

Unnecessary surgery in patients with inoperable diseaseshould be avoided by adequate and accurate preoperative

staging.

Alternatives to surgery in patients with incurable disease

should be actively considered.

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The simple option of a subpectoral expanding implant at the time of

primary surgery is diminishing, and more sophisticated approaches

using latissimus dorsi myocutaneous flaps to cover a prosthesis

are becoming more common. This has dramatically reduced the

incidence of the major complication of primary reconstruction:

infection and extrusion of the implant. The cosmetic results of a lat-

issimus dorsi flap and implant are superior to a simple subpectoral

expanding implant. The use of latissimus flaps to reconstructafter wide local excision to permit a larger volume of tissue to be

removed is also increasing, as is skin-sparing mastectomy, where

a relatively small amount of skin is excised.

This oncoplastic approach has disadvantages. The risk of infec-

tion is probably greater than a mastectomy without reconstruction,

and can take several weeks to resolve. This may have a significant

psychological effect and can delay adjuvant therapy. Radiotherapy

after primary breast reconstruction may be indicated if, for exam-

ple, axillary nodes are positive or the tumour is close to the deep

margin. Advanced radiotherapy techniques can be utilized, but

radiotherapy in the presence of a breast implant is technically

challenging and the long-term results are usually disappointing.

Reconstruction using abdominal flaps (e.g. TRAM, DIEP flaps)can achieve the most satisfactory cosmetic results, but at a greater

risk of flap loss and donor site problems. The overall appearance of

the reconstructed breast can be enhanced by nipple reconstruction.

The techniques are increasingly within the repertoire of specialist

breast surgeons who have appropriate training and expertise in

oncoplastic techniques.

Role of surgery in palliative care

Palliation should be an integral part of all steps in the patient

pathway, starting before diagnosis and continuing after death;

palliative care involves the care of patients who believe they

have malignancy, but are subsequently found not to and, at the

other extreme, bereavement support for relatives of terminally illpatients.

Most patients with common solid malignancies treated by

surgeons will be free of obvious metastases at the time of sur-

gery. Many will subsequently develop metastases and thus their

original surgery was palliative. In this sense, one major role of

surgery for malignancy is the relief of presenting symptoms and

the prevention of distressing symptoms due to the local progression

of malignancy. These include ulceration, bleeding, infection and

pain in breast cancer and anaemia; obstruction, perforation and

peritonitis in gastrointestinal malignancies. Nearly all malignancies

cause distressing symptoms due to local progression if not treated

adequately and surgeons preoccupation with local recurrence

rates is entirely appropriate in this context. For patients to undergomajor surgery only to develop early local recurrence is a failure

to fulfil the aims of cancer surgery and can result in symptoms

that are extremely difficult to palliate (e.g. pelvic recurrence after

surgery for rectal cancer). Some solid malignancies are commonly

associated with local failure before the development of terminal

distant disease, such as pelvic, gastro-oesophageal and pancre-

atic malignancies. It is in these areas that the role of adjuvant

radiotherapy and chemotherapy requires extensive exploration

and the technical aspects of surgery; balancing radical excision

with acceptable quality of life is crucial.

The role of reoperative abdominal surgery for complications due

to recurrence of gastrointestinal malignancy within the abdomen

is a common dilemma for surgeons. Standard investigations often

underestimate the extent of recurrence and it is not possible to

resect the disease at laparotomy. Occasionally, a localized recur-

rence may be resectable or a palliative bypass or stoma can be

done. Most surgeons believe that the terminal care of intestinal

obstruction is difficult and should generally be managed by non-

surgical treatments to reduce gastrointestinal secretions.

Orthopaedic surgeons play a major part in the provision of palli-ative surgery for patients with secondary bone disease, particularly

in breast malignancy. Patients presenting with painful metastasis

can be treated by localized radiotherapy in addition to analgesia,

but patients whose plain radiographs indicate imminent fracture of

a long bone (e.g. femur) may benefit from additional prophylactic

internal fixation. A substantial group of patients present with a

pathological fracture at some stage after their primary treatment;

these will not heal by conservative management and internal fixa-

tion or arthroplasty improves the care of these patients in terms

of symptom relief, mobilization and return home.

Summary

Surgeons are centrally involved in the diagnosis, care and follow-up

of patients with a wide number of malignancies. The important

skills required in the management of malignancy require further

definition and reflection in the training of future surgeons. In this

way, surgeons will remain vital to the multidisciplinary approach

to cancer management.

CROSS REFERENCES

Black J. Is increasing subspecialization going to improve surgical care?

Surgery2003; 21(1): iii.

Scholefield J H, Whynes D K. Screening for colorectal cancer in the UK: is

it worthwhile? Surgery2003; 21(7): iiivi.

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