treatment of oral carcinoms: surgical oncologist

1. Treatment of Oral Cavity
Carcinomas
Dr. Naina Kumar
10.1.2022

2. Goals
(1) cure of the cancer;
(2) preservation or restoration of speech, mastication, swallowing, and external appearance;
(3) minimization of the sequelae of treatment such as dental decay, osteonecrosis of the mandible, and trismus.

3. Staging
• The 2017 updated staging system includes important changes for patients with early-stage oral cavity cancer.
• Whereas prior iterations included only the maximum tumor size in a single plane (usually the surface), the AJCC eighth
edition staging system now also incorporates maximum depth of invasion (DOI).
• Patients with >5 mm DOI have a minimum tumor stage of T2; patients with >10 mm depth of invasion have a
minimum tumor stage of T3.
In one report of 27 patients with squamous cell carcinoma of the lower lip, there was a signi cant di erence in
mean DOI between patients with or without cervical lymph node metastases (5.6 versus 3.8 mm, respectively)
• Thus, patients with small but more deeply invasive tumors e ectively have higher-stage tumors.
• Patients with more extensive local disease, regional lymph node involvement, or distant metastasis have stage III or
IV disease.

4. Principle :
Early Stage Disease ( I & II Stage )
Single Modality Therapy - Surgery or RT
Locally Advanced Disease (Stage III & IV)
Combined Modality Therapy - Surgery & RT / CT-RT

5. When surgery over Radiotherapy ?
1. Site where surgery is not morbid (cosmetically and functionally)
2. Lesions involving or close to bone – to prevent radionecrosis.
3. Young patients – possibility of a subsequent second primary
4 Presence of sub mucous
fi
brosis (SMF)

6. When Radiotherapy is preferred over surgery ?
1. Severe impairment of function / cosmesis with surgery, e.g. base tongue, glottis
2. Surgery is technically di
ffi
cult with high morbidity and poor results e.g. nasopharyngeal carcinoma
3. Patient refuses surgery
4. High risk of surgery
sometimes applicable to early tumors of the retromolar trigone and lip since external RT can achieve similar outcomes to
surgery with acceptable morbidity.

7. Principles of Resection to remember:
En bloc resection of primary tumor whenever feasible
2. In continuity neck dissection when direct extension of primary into neck
3. Third dimension (the base) should be taken carefully into account before excision
4. Adequate margin: 1.5 – 2 cm
Clear margin: >/= 0.5 cm
Close margin < 0.5 cm
Every attempt should be made to ensure negative resection margins since positive margins are associated with
a worse prognosis.The UK Royal College of Pathologists have issued guidelines suggesting clear margins if the
histological clearance is > 5 mm, close margins if 1–5 mm and positive margins if < 1 mm.
5. Frozen section con
fi
rmation for margins may be done if the facility is available
6. Contralateral neck should be addressed when the probability of bilateral / contralateral metastases is high. Eg.
Tumours crossing the midline / midline tumours.

8. Management in Early oral cavity
lesion

9. Carcinoma in situ or micro invasive carcinoma
• Excision and biopsy with clear margins is adequate therapy. It should be exercised with 1 to 2 cm margin on the
peripheral and it aspects.
• Frozen sections are studied into operatively as severe dysplasia at the margin can be di cult to discern grossly.
• Early-stage cancers of the
fl
oor of mouth main involve the salivary duct and gain early access to the neck. Then oral
status requires careful assessment.
• Primary closure of the site is optimal if it can be accomplished without tethering the tongue or obligating normal
sulci .. One should allow the super
fi
cial defects to granulate. Healing by secondary intention is preferable to a closure
that impairs mobility.
• Occasionally a larger but very super
fi
cial lesion will be excised at the submucosal layer.
• SSG speeds recovery.

11. T1 and T2 lesions
• Five-year survival rates are 85 to 90% for stage one and 70 to 80% for stage two
carcinomas of oral cavity.
• If the primary site is treated surgically and there is concern over micro metastasis the
neck should be treated surgically as well. Likewise if the oral cavity is treated with
radiation, the lymphatic are treated similarly.
• Route of access is preferably trans-oral for smaller lesions. Margins must be clearly
visible however and patients with full dentition a limited oral opening can present
challenges. A lip split and/ or Mandibulotomy maybe required for adequate
visualisation of margins.
• Bone will not be grossly invaded in these early stage one and two lesions although
dysplastic mucosa or the main malignancy may approach the teeth or mandibular
Peri ostium.
• In general the Periostium is a e
ff
ective barrier if not previously radiated.

12. • If the tumour is freely mobile with relation to the bone, the Peri ostium is resected as
a margin and bone preserved. The alveolar surface of the mandible is vulnerable to
micro invasion and allows access to the medullary cavity through the tooth sockets.
The risk of micro invasion of the mandible is higher in edentulous or previously
irradiated mandible. When tumour directly invades the periostium, that segment of
mandible should be dissected with at least a rim mandibulectomy.
• The risk of micro metastasis to cervical lymphatics is increased proportionally with
depth of tumour invasion.
• As a general rule, tumours that measure greater than 4MM in thickness are at risk,
and treatment of cervical lymphatics should be considered.

13. • H&N squamous cell cancer with no clinical nodal involvement, rarely presents with
nodal metastasis beyond the con
fi
nes of an appropriate selective neck dissection
(<10% of the time).
• Level V involvement in oral cavity ca is approx 1%.
• Approx 30-35% of patients with cN0 are found to have histological eveidence of
malignancy in cervical nodes(pN+).

15. T3 and T4 Carcinoma of the Oral Cavity
• Large oral cavity cancers and those that deeply invade the tongue, bone, or adjacent spaces require multimodal
therapy. Survival rates for T3 and T4 squamous cell carcinoma of the oral cavity are 50% to 65% in the absence
of nodal metastases.
• Nodal metastases generally cut survival rates in half.
• Primary surgical resection remains the preferred initial treatment option.

16. • Edentulous patients with pliable perioral soft tissue may not require a lip split for access from the oral side. Again, if
visualization of the margins is impaired, lip split or mandibulotomy is recommended as necessary to allow proper
exposure. Complete tumor resection should be the primary concern.
• Gross invasion of the mandible mandates a segmental resection. Whenever possible, the entire medullary cavity of
the mandible should be resected. Tumor invading the mandible can spread widely through the loose cancellous bone.
For example, if a lesion invades the midbody of the mandible, segmental resection of bone with a 2-cm margin is
combined with rim removal of the remaining medullary cavity back to the sigmoid notch.

17. Segmental Mandibulectomy
Indication:
• Gross bony erosion
• Received radiotherapy
• Edentulous mandible
• Gross Periosteal involvement
• Gross Paramandibular disease
• Whenever inferior soft tissue and bony margin of 1 cm is not possible.

18. Site specific surgical
management

19. Floor of Mouth
• The
fl
oor of mouth is the most common site for oral squamous cell carcinoma. The adjacent ventral tongue and lingual
surface of the mandibular alveolus are involved early as the tumor enlarges.
• Anteriorly,
fl
oor-of-mouth lesions often involve the submandibular ducts and contralateral nodes are at risk.
• CT scans are useful in preoperative staging to assess tumor extent, nodal status, and early mandibular invasion.

21. T1 and T2 Carcinoma of the Floor of Mouth
• T1 and T2 lesions of the
fl
oor of mouth are treated with wide local excisio
• A margin of 2 cm is recommended and frozen section control of margins intraoperatively may avoid overlooking
severe dysplasia in surprisingly normal-appearing mucosa.
• Lesions deeper than 4 mm have a higher incidence of nodal metastasis, and an elective selective neck dissection
should be considered.
• Transoral access without lip split or mandibulotomy is often possible.
• Full dentition or poor oral opening can make access surprisingly di cult for small lesions. The patient should be
prepared for mandibulotomy for access should this occur.

22. • When deep dissection in the lateral
fl
oor of mouth is combined with level 1 neck dissection, a through-and-through
defect often results that can be surprisingly di
ffi
cult to close.
• Pedicled
fl
aps such as the platysma
fl
ap or submental island ap are useful to close these small defects. Radial
forearm free
fl
aps work very nicely as well. Pectoralis
fl
aps are often too bulky for small defects in this site.

23. T3 and T4 floor-of-mouth lesions
• resected in conjunction with cervical lymphadenectomy. A reasonable plan of surgical progression is outlined below.
These steps will be adaptable for other subsites in the oral cavity as well.
1. Repeat examination under anesthesia. Assess size, depth, structures involved, and proximity to mandible. Finalize
thoughts on access and bone invasion.
2. Tracheotomy inmost circumstances .
3. Percutaneous gastrostomy. If a short period of tube feeding is
anticipated, place a nasogastric tube at the conclusion instead.

24. • Neck dissection. Extent determined by nodal status.
• Approach primary. Split lip and perform stair-step mandibulotomy anterior to the mental foramen if necessary for
access *

27. • The osteotomy should be conducted anterior to the mental foramen to preserve labial sensation. The preferred
site for the osteotomy is the paramedian area (between the lateral incisor and canine) since the distance between
the tooth roots is greater.
• An osteotomy in the paramedian area preserves the attachments of geniohyoid, genioglossus and digastric to the
major segment, only mylohyoid requiring division to mobilize the minor segment. If the distance between the lateral
incisor and canine roots is insufcient to accept a saw blade then the lateral incisor should be removed and the
osteotomy conducted through the socket to minimize the possibility of osteoradionecrosis should a tooth be
damaged

28. • For large tumors with gross bone invasion, plan the mandibulotomy at the anterior margin of bone resection. Bend
and apply reconstruction or fracture plates prior to cutting bone unless the tumor extends through the lateral cortex.
This step optimizes dental occlusion postoperatively. If segmental composite resection is planned, tumor visualization
will be easier if the posterior bone cuts are completed at this time as well
• For tumors that contact the mandible without gross bone destruction, perform a rim mandibulectomy to remove the
occlusal surface and medullary cavity of the involved bone.
• Take care in edentulous patients as the inferior mandibular remnant may be very thin and prone to pathologic
fracture.

29. Cancer of the
fl
oor of mouth has a high rate of
mandibular invasion and cervical lymph node
metastases. Furthermore, anterior
fl
oor of mouth
cancers often involve the geniohyoid tubercle and
genioglossus muscle anteriorly. Thus, surgery will
frequently require segmental mandibulectomy as a
marginal resection of bone is generally not possible
in the coronal plane.

30. • A modied mandibulotomy where only the buccal cortex is cut with a saw, the lingual plate being fractured with a
small osteotome, has been described so ensuring bone-to-bone contact at the end of the procedure and may lead to
better osseous healing.The mandible and cheek ap may now be retracted laterally and superiorly giving excellent
access to the posterior oral cavity and oropharynx.
• Distract the mandible at the anterior osteotomy and visualize tumor margins.
• Make mucosal cuts 2 cm from obvious disease.
• Surgical resection of the oor of mouth in the majority of circumstances will involve resection of part of the
submandibular ducts. Typically the ducts will be transected at the resection margin, well away from their orice,
although in smaller resections at least 3 mm length of duct proximal to the orice should be taken to ensure surgical
clearance of carcinoma or dysplasia that may extend along the duct.

31. • Management of the submandibular ducts is of great importance if a neck dissection is not being conducted with
consequent removal of the submandibular gland. Stricture of the duct in the presence of a functioning gland may give
rise to obstructive symptoms of the gland and difculty in di erentiating the potential submandibular gland swelling
from cervical disease.
• The ducts should be transected obliquely to minimize stricture formation and repositioned at the margin
of resection, ideally being stented. Alternatively, the ducts may be found proximal to the resection margin, a
longitudinal incision made and the duct ‘marsupialized’ to the oor-of-mouth mucosa. Uninvolved branches of
the lingual nerve should be identied and preserved.
• As dissection progresses deeper, revisualize the hypoglossal nerve in the neck as it will often enter the tongue medial
to the tumor and can be preserved. Control lingual artery branches with ligatures. Do not rely on cautery for the larger
branches.
• Remove the specimen and inspect. Orient the specimen for pathology. Check margins with frozen sections.
• Inspect the defect and determine closure method. Avoid primary closure under tension or closures that will
signi
fi
cantly tether the tongue. Often, the reconstructive team will have proceeded with ap elevation during the nal
phases of tumor extirpation.

32. Tongue carcinomas

33. T1 and T2
• Tongue cancers frequently have submucosal extension well beyond the visible margin. Palpation and imaging studies
are helpful in accurate staging.
• T2 and deep T1 (>4 mm) tongue cancers have occult metastatic rates approaching 30%. Treatment of the neck is
usually recommended.
• Small lateral tongue lesions can be widely excised with very little morbidity. These malignancies are generally more
easily visualized than
fl
oor-of-mouth lesions and rarely require lip split or mandibulotomy.
• If possible, a deep wedge resection is designed in a vertical plane maintaining 2-cm margins at the peripheral and
deep margins.

35. • The vertical resection allows closure of lateral tongue to corresponding lateral tongue and minimizes tethering
• Horizontal closure, in contrast, tethers the dorsal tongue to the oor of mouth and impairs mobility. Resection of
super
fi
cial T2 tumors of the lateral tongue results in a defect involving most of the lateral surface .These defects
should be covered with a thin skin graft or allowed to granulate. The patient begins tongue mobility exercises early to
prevent scar contracture and loss of function.
• Dorsal tongue cancers are less common. These lesions are resected in a sagittal plane if possible and closed
primarily. Function is usually excellent.

37. • Large lateral tongue lesions are approached as described above under “Floor of Mouth.” Osteotomies render the
resection easier because the exposure is generous. These resections are the classic “commando” or “tongue–jaw–
neck” procedures described for decades in the head and neck literature.**
• Primary closure of the buccal mucosa to the tongue remnant is often possible and speech and swallowing function
are surprisingly good. The patient is unable to chew, however, and the appearance is dramatically altered. Immediate
fl
ap reconstruction is usually employed in modern resections.
• Preservation of the tip of the tongue, while maintaining oncologically sound resection margins, helps
maximize post-operative function. The use of monopolar electrocautery, ‘cutting’ through mucosa changing
to ‘coagulation’ when in muscle, or the harmonic scalpel helps reduce bleeding during the resection,
however this is at the cost of lack of feel a
ff
orded by the use of scalpel or scissors. If both lingual vessels are
resected then the viability of the tip of tongue remnant should be carefully assessed.

39. • For lesions that extend more centrally into the deep root of tongue musculature, an alternative pull-through approach
to resection is required.
• The steps are discussed below:
• Neck dissection should be bilateral for deep lesions extending toward the central tongue. A visor ap of the neck skin
is raised to the inferior border of the mandible

40. • No lip split is usually required for access. The
uninvolved
fl
oor-of- mouth mucosa is incised on
the side of the tumor and continued onto the
uninvolved contralateral tongue, maintaining 2-cm
margins.
• Dissection will frequently extend across the
midline. The mylohyoid muscle is transected from
below. Working from above and below, the
dissection progresses until the anterior and lateral
cuts communicate from neck to oral cavity.
• The specimen is then delivered downward, under
the intact mandible and into the neck. Following
this maneuver, visualization of the posterior cuts is
simpli
fi
ed and resection is completed.

41. • Assess margins grossly and by frozen section. Do not overlook deep tongue margins, which will extend down to the
hyoid bone.
• With an intact mandible, these lesions are nearly impossible to close without a pedicled or free ap.
• If a large volume of tongue muscle is resected, the
fl
ap reconstruction should provide su cient bulk to allow the neo-
tongue to contact the palate. This will optimize speech and swallowing postoperatively. A radial forearm ap may
not provide adequate volume in this setting.

42. Buccal Mucosa and Retromolar
Trigone

43. T1 and T2
• Nodal metastases occur early (40% for T2 lesions in one meta-analysis). Early-stage carcinomas of this region are
treated in a fashion similar to the
fl
oor of mouth.
• Wide local excision with 2-cm margins is recommended and primary closure for smaller defects is usually easily
accomplished. Thin skin grafts also provide adequate coverage if the underlying buccinator muscle is intact.
• For all but the most super
fi
cial lesions, the buccinator should be taken as the deep margin of resection. Failure rates
for early buccal carcinomas are high. Treatment of T1/T2 retromolar trigone lesions is similar.

45. T3 and T4
• Large tumors of the buccal mucosa or retromolar trigine are di cult to manag
• The head and neck surgeon should keep the following facts in mind when planning treatment for advanced tumors in
this region:
• 1. The layers of the buccal region are buccal mucosa, submucosa, buccinator muscle, subcutaneous fat, and
cheek skin. Once a lesion is deep enough to invade the buccinator muscle, the overlying cheek skin is
potentially involved. Resection frequently results in a through-and- through defect requiring at minimum local
fl
ap coverage.The primary tumour should be resected with a 1 cm margin,and up to 2 cm if skin is involved.
• 2. Deep posterior invasion from both buccal and retromolar trigone tumors extends toward the masseteric
space. Meticulous attention to this potential direction of spread is required to avoid local recurrence

47. 3 The retromolar trigone mucosa provides
reasonably thin cover over the ascending
mandible. Larger tumors quickly invade the bone
and continue into the masticator space.
4. Retromolar trigone tumors often extend
posteriorly into the oropharynx. Many clinicians
consider the biologic behavior to be more
consistent with oropharyngeal carcinoma than
oral cavity carcinoma. When there is bulky
extension into the tonsil or soft palate,
concurrent radiation and chemotherapy are given
more consideration as
fi
rst-line therapy to
preserve speech and swallowing function. As is
true for other oral cavity sites, however, no
treatment has been proven superior to surgery
and adjuvant radiation for buccal or retromolar
trigone carcinomas.

48. • 5. Perifacial nodes and parotid nodes are
fi
rst-level nodal basins for these tumors.
• 6. Transoral exposure may be limited. Be prepared for a transfacial approach to improve access.
Patients with good dentition are often candidates for marginal resection of the mandible, which can be
performed transorally. In contrast, edentulous patients and those with loose teeth involved by cancer require
segmental resection of the mandible to ensure adequate clearance of disease.
Similarly, locally advanced retromolar trigone lesions typically require segmental mandibulectomy followed by
postoperative RT. Resection of the ascending ramus of the mandible including the pterygoid muscles is
important to ensure eradication of disease.

49. Hard Palate

50. T1 and T2
• All but the most super
fi
cial palatal lesions have the potential to invade underlying bone.
• The incisive and greater palatine foramina also provide pathways for perineural dissemination.
• Thin lesions of the hard palate may be managed with wide local excision. Peripheral margins are managed as
discussed above.
• If uninvolved periosteum is interposed between the tumor and underlying bone, bone resection may be unnecessary.
If any doubt exists, palatal bone can be drilled away down to nasal mucosa without creating an oronasal stula. If a
small
fi
stula must be created, a rotational
fl
ap of palatal mucosa or a buccinator myomucosal ap will usually close
the defect e
ff
ectively.

51. T3 and T4
• Larger palatal lesions characteristically involve bone. Preoperative CT scans are very helpful in assessing superior
extension of disease into the nose or maxillary sinus. **
• An inferior maxillectomy is usually required for complete resection. These lesions may escape posteriorly into the
pterygoid plates and pterygoid musculature and extend to the skull base. The pterygomaxillary space and foramen
rotundum are sites of disease persistence in deeply invasive palatal carcinoma.
• Reconstruction of palatal defects is essential for speech and swallowing. Reconstruction can be either prosthetic or
surgical. A temporary dental obturator can be placed intraoperatively or after the rst postoperative visit around day
10.

53. • A
fi
nal obturator can be fashioned a few months later
when soft tissue contraction has stabilized. The
advantages are an open cavity for tumor surveillance
and no additional surgical morbidity for the patient. The
disadvantage is the requirement to maintain a well-
fi
tting
obturator in order to enjoy normal speech and
swallowing. Many patients are frustrated by minor leaks
or pain with an improper
fi
t.
• Surgical closure of larger defects typically requires free
fl
ap reconstruction.
• If doubt about margins remains, a temporary obturator
can easily be fashioned and the defect reconstructed
secondarily

55. Thank you